RU2753146C1 - Waveguide with holographic and diffraction optical elements, method for manufacture thereof, virtual and augmented reality apparatus containing such waveguide, and method for operation thereof - Google Patents

Abstract

FIELD: waveguides.

SUBSTANCE: invention relates to the field of waveguide-based virtual and augmented reality apparatuses. Claimed is a method for manufacturing a waveguide with diffraction optical elements, including: providing a waveguide, fixing fragments of one or more holographic media on the waveguide; recording a diffraction optical element constituting a holographic optical element in each fragment of the holographic medium using a pre-distorted object wave containing phase-conjugated aberrations to the aberrations of the inspection wave, detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the holographic medium. Also provided is a waveguide with diffraction optical elements manufactured according to the above method, a virtual and augmented reality apparatus containing such waveguide, and a method for operation thereof. Also proposed is a method for manufacturing a waveguide with diffraction optical elements recorded in fragments of one or more recorded diffraction media, a waveguide with diffraction optical elements manufactured according to the above method, a virtual and augmented reality apparatus containing such waveguide, and a method for operation thereof.

EFFECT: provided is compact and cheaper virtual and augmented reality apparatus containing a waveguide with holographic and diffraction optical elements due to elimination of the need for pre- and post-processing of images introduced into the waveguide and the possibility of using non-ideal waveguides and holographic media.

54 cl, 11 dwg

Description

FIELD OF THE INVENTION

The invention relates to the field of virtual and augmented reality (VR and AR) waveguide devices, for example, virtual and augmented reality glasses, virtual and augmented reality displays, virtual and augmented reality helmets, dashboards on the windshield, indicators on the windshield. More specifically, the invention relates to the creation of virtual and augmented reality devices that are located near the user's eye and from which a virtual image is directed into the user's eye. Even more specifically, the invention relates to virtual and augmented reality devices, containing a waveguide with diffractive and holographic optical elements, and methods of making such waveguides.

BACKGROUND OF THE INVENTION

The technology of virtual and augmented reality devices is based on the superposition of a virtual image on a real picture of the environment. Modern virtual and augmented reality devices are mainly based on waveguide technology with structures of diffractive or holographic optical elements for directing a virtual image into the human eye. In addition to wide field of view (FOV), compactness, light weight and reasonable cost, virtual and augmented reality devices must provide high-resolution images without aberrations.

To provide high quality virtual images in virtual and augmented reality waveguide devices with diffractive or holographic optical elements of the prior art, it is necessary to pay attention to the quality of wavefronts transmitted through the waveguide system. Possible defects or inhomogeneities inherent in the waveguide and holographic media themselves can cause wavefront aberrations and, thus, reduce the quality of the virtual image. To correct such aberrations, it is necessary to take special measures at the stage of production or operation of virtual and augmented reality devices.

Degradation in image quality in prior art virtual and augmented reality devices 101 is shown schematically in FIG. 1, where the passage of the image from the projector 102 of the device 101 of virtual and augmented reality to the user's eye is conventionally divided into four stages:

In step (I), the original image 103 is input into the waveguide 104 from the image projector 102 of the virtual and augmented reality device 101.

At stage (II), the original image 103 is transmitted through the structure of the waveguide 104 with diffractive or holographic optical elements (106, 107, 108), which has defects (inhomogeneity, non-flatness, etc.).

The original image 103, passing through the diffractive or holographic optical elements 106, 107, 108, as well as through the waveguide 104 itself until reaching the user's eye, acquires aberrations, since defects in the structures of the diffractive or hologram optical elements and the waveguide cause distortion of wave fronts propagating through them. For example, if a plane input wave 105 is applied to the input diffractive or hologram optical element 106 of the waveguide, then the output wave 109 with aberrations will be obtained at the output hologram or diffractive optical element 108 of the waveguide due to the above-mentioned defects.

In step (III), it is shown that, in the absence of special measures, when the image is fed from the waveguide 104 directly into the user's eye, the user will see not the original image 103, but the image 110 containing aberrations.

Therefore, in devices of virtual and augmented reality of the prior art, at stage (IV), post-processing is performed on the image that has passed the structure of the waveguide 104 with diffractive or hologram optical elements 106, 107, 108, after which the aberration-free corrected virtual image 111 can be fed into the user's eye. ...

The general approach to image correction in prior art virtual and augmented reality devices is that in order to supply a high-quality virtual image to the user's eye, additional elements must be used as part of a virtual and augmented reality device to correct the aberrations of an image that has passed through the structure of a waveguide with diffraction or holographic optical elements. However, this complicates the design of devices, makes them more massive and more expensive.

Personalized correction and optimization of high-order aberrations of the human eye using binoculars, telescopic sights, telescopes, microscopes, night vision goggles and laser eye protection introduced by optical elements is disclosed in US 8842370 B2.

The disadvantages of this technical solution are associated with the fact that for the correction of aberrations, an additional corrective element is used, which is a three-layer structure of polymer, which is specially manufactured and built into the device. The correcting element has a limited life.

The technical solution disclosed in US 8717574 B2 is aimed at reducing the effects of scattering in a highly turbid environment by optical phase conjugation. The detector of radiation passing through the turbid medium comprises one or more digital optical phase conjugation (DOPC) devices, and the digital optical phase conjugator includes a wavefront sensor (in this case, a CCD array) of radiation that has been transmitted through the turbid medium and introduced on the sensor; and a spatial radiation modulator (SLM) for outputting, in response to the input radiation detected by the sensor, an output radiation that is optically phase conjugate with the input radiation.

The disadvantage of the technical solution is that the update rate of the digital optical phase conjugator is determined by the rate of the spatial radiation modulator used, i.e. dynamic use constraints.

WO 2014/159621 A1 is directed to improving the image quality of a waveguide display system. The display device includes a waveguide, a tunable phase mask, and a controller. The controller dynamically adjusts the tunable phase mask so as to modulate the display light in accordance with the detected position of the eye viewing the image and / or the waveguide shape parameter.

The disadvantage of this solution is associated with the fact that the waveguide display system has a special controller for electronic image correction, which complicates the design and makes it more cumbersome.

US 2019/0260977 A1 discloses the projection of an image and a wavefield through diffuse media. A system for projecting an object wave field into a projection volume includes a wave diffuser, a wave field projector configured to project the wave field onto the wave diffuser, and a controller associated with the wave field projector. The controller is configured to issue a command to the wave field projector to project the wave field, which, when interacting with the wave scatterer (diffusion object (s)), is redirected to form an object wave field that forms a given pattern in the projection volume.

To obtain an undistorted image in this document, a preliminary distortion of the image is performed, which then propagates through diffuse objects. In this case, to calculate the transmission matrix of a diffusion object, a special calibration procedure is used, which complicates the operation of the device and requires the use of additional elements to correct the image.

US 10394032 B2 relates to systems and methods for transmitting an original image. Radiation emanates from the original image, which has a field angle spectrum. The optical system includes a waveguide device in which radiation can be propagated by total internal reflection. The optical system also includes a diffractive optical input device for inputting radiation emanating from the image source into the waveguide, and a diffractive optical output device for outputting radiation that propagates in the waveguide from the waveguide. In this case, the waveguide is equipped with a diffraction correcting device having a diffraction grating structure for correcting the wavefront aberrations of the transmitted radiation.

The disadvantages of the device are associated with the complex structure of the waveguide device, which is due to the presence of a special correcting device. In addition, a proper correction device must be designed for a specific waveguide and grating structure.

US 2018/0364482 A1 discloses a holographic display system comprising a waveguide, a radiation source configured to input radiation into the waveguide at a controlled radiation input angle, and a hologram optical element (HOE) configured to output radiation received from the inside of the waveguide from the waveguide. The display system may further include a controller configured to control the radiation input angle as well as control a correction component located downstream of the hologram optical element to correct the radiation aberration of the hologram optical element based on the radiation input angle.

The disadvantage of this device is associated with the fact that a special corrective element based on a hologram optical element is used to compensate for radiation aberrations, and the correction processing is performed using a controller, which complicates the design of the device and makes it more expensive.

Thus, there is a need for the development of simpler and cheaper devices that ensure the preservation of the quality of the image transmitted through the waveguide.

SUMMARY OF THE INVENTION

In view of the above technical problems, the present invention will now be described by way of example and not limitation, with reference to the description and drawings below.

This Summary of the Invention precedes the detailed description of specific exemplary embodiments to provide an overview of aspects of the claimed invention that will be further explained below, and is in no way intended to define or limit the scope of the present invention in any way.

The object of the present invention is the preservation of the quality of the image transmitted through the waveguide when using aberration-introducing (non-ideal) waveguides and diffraction and holographic media and without the use of optical / electronic pre- and post-processing of images.

The technical result of the present invention is to provide a compact and cheaper virtual and augmented reality device containing such a waveguide, due to the elimination of the need for pre- and post-processing of images entered into the waveguide and the possibility of using non-ideal waveguides and diffractive and holographic media.

In one aspect of the present invention, there is provided a method for manufacturing a holographic optical element waveguide, comprising:

- providing a waveguide,

- fixation on the waveguide of fragments of one or more holographic environments;

- recording in each fragment of the holographic environment holographic optical element using a predistorted object wave containing phase-conjugate aberrations to the aberrations of the inspection wave, detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the holographic medium.

In one embodiment, an inspection wave is passed through each local structure formed by a waveguide and a piece of holographic medium.

In one embodiment, aberrations of an inspection wave that have passed through a local structure formed by a waveguide and a fragment of a holographic medium can be detected using a Shack-Hartmann wavefront sensor, a CCD, or a CMOS sensor.

In another embodiment, the phase conjugate aberrations can be calculated using the phase and amplitude values of the inspection wave obtained by phase shifting interferometry.

In yet another embodiment, once computed, the phase conjugate local aberrations can be stored on a computer-readable storage medium.

According to another embodiment, the predistorted object wave can be generated by distorting the object wave with micromirror, liquid crystal, or acousto-optic space-time light modulators based on the calculated phase conjugate aberrations.

In another embodiment, the holographic optical element is recorded with a predistorted object wave and an undistorted reference wave .

According to another embodiment, the phase-conjugate aberrations compensate for aberrations that occur when the object wave travels along the same optical path that was used to detect aberrations by an inspection wave that passed the local structure formed by the waveguide and a fragment of the holographic medium, and when the holographic optical element was recorded in fragment of the holographic environment.

In another embodiment, the holographic media may include photopolymers, photothermoplastics, photochromic materials, photothermorefractive materials, photoresists, silver halide photographic materials, or dichromated gelatin.

According to another embodiment, the fragment of the holographic medium can be in the form of a film or layer of a given thickness and geometric shape.

According to another embodiment, each holographic optical element is recorded so that it deflects and / or guides waves propagating along the waveguide and compensates for aberrations caused by the local structure formed by the waveguide and a fragment of the holographic medium in which the optical element is recorded.

In another embodiment, the hologram optical element may be a transmissive or reflective hologram element.

In yet another embodiment, the inspection wave may be plane or spherical, or have a specially selected wavefront shape, wherein the reference wave is plane or spherical, or has a specially selected wavefront shape.

In another embodiment, the inspection wave can be applied at an arbitrary angle to the surface of the waveguide.

According to another embodiment, the predistorted object wave during recording of the optical element can be applied at an arbitrary angle to the waveguide surface, while the angle of incidence of the predistorted object wave on the waveguide surface is equal to the angle of incidence of the inspection wave on the waveguide surface when detecting aberrations.

According to another embodiment, each of said holographic optical elements is fixed to a waveguide at a predetermined location.

In another embodiment, the waveguide and fragments of said one or more holographic media may have defects that cause aberrations as waves propagate through them.

In another embodiment, the waveguide can be flat or curved.

In another aspect of the present invention, there is provided a holographic optical element waveguide fabricated by the method described above.

According to one embodiment, said hologram optical elements may comprise one or more input hologram optical elements for inputting an image into a waveguide, one or more multiplying hologram optical elements configured to increase the geometric dimensions of the transmitted image, and one or more output hologram optical elements for outputting images from the waveguide.

In yet another aspect of the present invention, there is provided a virtual and augmented reality device comprising a holographic optical waveguide fabricated in the manner described above.

According to one embodiment, the device can be configured to input the original image from the image source into the waveguide, increase the geometric dimensions of the image, and output a virtual image free from aberrations from the waveguide to the user's eye.

According to another embodiment, the device can be configured to compensate for aberrations caused by local structures of the waveguide with holographic optical elements when transmitting an image over the waveguide with holographic optical elements.

In another embodiment, the image source can be a projector.

In yet another aspect of the present invention, there is provided a method for operating a virtual and augmented reality device comprising a waveguide with holographic optical elements, the method comprising:

- supply of the original image to the waveguide with holographic optical elements from the image source,

- image transmission over a waveguide with holographic optical elements with compensation for aberrations caused by local structures of a waveguide with holographic optical elements,

- output of a virtual image, free from aberrations, from a waveguide with holographic optical elements into the user's eye.

In another embodiment, the method may comprise increasing the geometric dimensions of the image while transmitting the image over the waveguide.

In another aspect of the present invention, there is provided a method of making a waveguide with diffractive optical elements, comprising:

- providing a waveguide,

- fixation on the waveguide of fragments of one or more recorded diffraction media;

- recording in each fragment of the recorded diffraction medium a diffractive optical element using a predistorted object wave containing phase conjugate aberrations to the aberrations of the inspection wave detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the recorded diffractive medium.

In one embodiment, the recording diffractive media may include diffractive structures and holographic media.

In yet another further embodiment, said diffractive structures include diffractive structures on photoresists and diffractive structures on chalcogenide materials.

In one embodiment, the holographic media may include photopolymers, photothermoplastics, photochromic materials, photothermorefractive materials, photoresists, silver halide photographic materials, or dichromated gelatin.

In one embodiment, an inspection wave is passed through each local structure formed by a waveguide and a piece of a recorded diffractive medium.

In one embodiment, aberrations of an inspection wave that have passed a local structure formed by a waveguide and a fragment of a recorded diffractive medium can be detected using a Shack-Hartmann wavefront sensor, CCD, or CMOS sensor.

In one embodiment, phase conjugate aberrations can be calculated using phase and amplitude values of the inspection wave obtained by phase shifting interferometry.

In yet another further embodiment, once computed, the phase conjugate local aberrations may be stored on a computer-readable storage medium.

In yet another embodiment, the predistorted object wave can be generated by distorting the object wave with micromirror, liquid crystal, or acousto-optic space-time light modulators based on the calculated phase conjugate aberrations.

In one embodiment, the diffractive optical element is recorded with a predistorted object wave and an undistorted reference wave .

In a further embodiment, phase-conjugate aberrations compensate for aberrations that occur when the object wave travels along the same optical path that was used to detect aberrations by an inspection wave that passed the local structure formed by the waveguide and a fragment of the recorded diffractive medium, and when the diffractive optical element was recorded in fragment of the recorded diffraction medium.

In an additional embodiment, the portion of the recorded diffractive medium may be in the form of a film or layer of a given thickness and geometry.

In a further embodiment, each diffractive optical element is recorded so that it deflects and / or guides waves propagating along the waveguide and compensates for aberrations caused by the local structure formed by the waveguide and the fragment of the recorded diffractive medium in which the optical element is recorded.

In a further embodiment, the diffractive optical element may be a transmissive or reflective diffractive element.

In yet another additional embodiment, the inspection wave can be plane or spherical, or have a specially selected wavefront shape, the reference wave being plane or spherical, or has a specially selected wavefront shape.

In yet another additional embodiment, the inspection wave can be applied at an arbitrary angle to the surface of the waveguide.

In another additional embodiment, the predistorted object wave during recording of the diffractive optical element can be applied at an arbitrary angle to the waveguide surface, while the angle of incidence of the predistorted object wave on the waveguide surface is equal to the angle of incidence of the inspection wave on the waveguide surface when detecting aberrations.

In yet another additional embodiment, each of said diffractive optical elements is fixed to the waveguide at a predetermined location.

In yet another further embodiment, the waveguide and portions of said one or more recordable diffractive media may have defects that cause aberrations as waves propagate therethrough.

In yet another additional embodiment, the waveguide can be flat or curved.

In another aspect of the present invention, there is provided a diffractive optical element waveguide fabricated by the method described above.

In a further embodiment, said diffractive optical elements may comprise: one or more input diffractive optical elements for inputting an image into a waveguide, one or more multiplying diffractive optical elements configured to increase the geometric dimensions of the transmitted image, and one or more output diffractive optical elements for image output from the waveguide.

In another aspect of the present invention, there is provided a virtual and augmented reality device comprising a diffractive optical element waveguide fabricated in the manner described above.

In an additional embodiment, the virtual and augmented reality device can be configured to input the original image from the image source into the waveguide with diffractive optical elements, increase the geometric dimensions of the image and output a virtual image free from aberrations from the waveguide with diffractive optical elements into the user's eye.

In an additional embodiment, the virtual and augmented reality device may be configured to compensate for aberrations caused by local structures of the diffractive optical element waveguide when the image is transmitted over the diffractive optical element waveguide.

In another embodiment, the image source can be a projector.

In another aspect of the present invention, there is provided a method for operating a virtual and augmented reality device comprising a waveguide with diffractive optical elements, the method comprising:

- supply of the original image to the waveguide with diffractive optical elements from the image source,

- image transmission through a waveguide with diffractive optical elements with compensation for aberrations caused by local structures of a waveguide with diffractive optical elements,

- output of a virtual image, free from aberrations, from a waveguide with diffractive optical elements into the user's eye.

According to another embodiment, said method may comprise increasing the geometric dimensions of an image during image transmission through a waveguide with diffractive optical elements .

BRIEF DESCRIPTION OF DRAWINGS

Based on the above objectives of the present invention and its aspects, specific exemplary embodiments of the claimed invention will now be described in detail, which should be considered in conjunction with the accompanying drawings and which are in no way intended to define or limit the scope of the invention, but only to disclose specific examples of it. implementation. Other embodiments, modifications, or equivalent substitutions will be apparent to those of skill in the art based on this disclosure, and all such embodiments, modifications, and equivalent substitutions are intended to be included in the present invention.

The drawings are provided solely for the purpose of illustration as an aid to reading and to understand the description, and should not be construed in any way as defining or limiting the scope of the invention. The drawings show the following:

Figure 1 shows a diagram of the passage of an image from a projector to a user's eye in a prior art virtual and augmented reality device.

Figure 2 shows a diagram of the passage of an image from a projector to a user's eye in a virtual and augmented reality device according to the present invention.

Figure 3 shows a manufacturing sequence of a waveguide with holographic optical elements according to an embodiment of the present invention.

Figure 4 shows various embodiments of a wavefront and phase conjugation unit.

Figure 5 illustrates a manufacturing sequence for a holographic optical element waveguide using a photosensitive waveguide.

Figure 6 illustrates the manufacturing sequence of a waveguide with holographic optical elements based on holographic media with a very low recording threshold.

Figure 7 is a schematic representation of a holographic optical element waveguide manufactured by the method of the present invention.

Figure 8 illustrates a case of aberration compensation using a thin holographic medium.

Figure 9 illustrates the manufacturing sequence of a waveguide with diffractive optical elements, where the diffractive optical elements can be written in diffractive structures on photoresists and in diffractive structures in chalcogenide materials.

Figure 10 illustrates the manufacturing sequence of a waveguide with diffractive optical elements, where the diffractive optical elements can be written in diffractive structures on photoresists and in diffractive structures in chalcogenide materials.

Figure 11 is a schematic representation of a virtual and augmented reality device containing a waveguide with diffractive optical elements, where the diffractive optical elements include diffractive optical elements recorded in diffractive structures on photoresists, diffractive optical elements recorded in diffractive structures in chalcogenide materials, and holographic optical elements (i.e., diffractive optical elements recorded in holographic media).

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention was made in view of a number of known solutions demonstrated above, and is directed, in particular, to eliminate and / or mitigate at least some of the disadvantages of these known solutions.

In particular, embodiments of the present invention provide a method for manufacturing a waveguide with holographic optical elements, comprising: providing a waveguide, fixing fragments of one or more holographic environments; recording in each fragment of the holographic medium holographic optical element using a predistorted object wave containing phase-conjugate aberrations to the aberrations of the inspection wave, detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the holographic medium. In addition, embodiments of the claimed invention provide a holographic optical waveguide manufactured by the above method, a virtual and augmented reality device comprising such a holographic optical waveguide, and a method for operating the device.

In addition, embodiments of the present invention provide a method for manufacturing a waveguide with diffractive optical elements, comprising: providing a waveguide, fixing fragments of one or more recorded diffraction media; recording in each fragment of the recorded diffraction medium a diffractive optical element using a predistorted object wave containing phase conjugate aberrations to the aberrations of the inspection wave detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the recorded diffractive medium. In addition, embodiments of the claimed invention provide a diffractive optical element waveguide manufactured by the above method, a virtual and augmented reality device comprising such a diffractive optical element waveguide, and a method for operating the device.

It will be understood by those skilled in the art that the various exemplary embodiments are not to be construed in any way as defining or limiting the scope of the claimed invention, and that other material and technical means, equivalent or explicitly similar to those listed below, may be provided by those skilled in the art to perform various operations. , functions, method steps, etc., described below. The present detailed description is not intended to define or limit the scope of the claimed invention, which should be determined only by reference to the appended claims.

The term "diffractive optical element, DOE" used in this document means an optical element that converts transmitted (reflected) optical radiation as a result of diffraction on its microstructure with a constant or variable period according to a given law.

The term "transmissive diffractive optical element" as used herein means a diffractive optical element that converts incident optical radiation as it passes through the element.

The term "reflective diffractive optical element" as used herein means a diffractive optical element that converts incident optical radiation as it is reflected from the element.

The term "holographic optical element; "GOE" used in this document means a diffractive optical element, manufactured both by methods of interference of light waves, and by methods of laser and electron lithography.

The term "transmissive holographic optical element" as used herein means a holographic optical element that converts incident optical radiation as it passes through the element.

The term "reflective hologram optical element" as used herein means a holographic optical element that converts incident optical radiation as it is reflected from the element.

The term "inspection wave" as used herein means a weak, low-energy wave used to detect aberrations acquired by this wave as it propagates through one or more objects whose physical properties give rise to these aberrations.

The term "object wave" used in this document means one of the waves forming an interference pattern when obtaining a holographic optical element, which contains information intended for reproduction or transformation. In the case of a transmissive hologram element, the object wave is formed by radiation transmitted through the object; in the case of a reflective hologram element, reflected from an object.

The term "reference wave" as used herein means one of the waves that form an interference pattern when obtaining a holographic optical element, which is usually used to reconstruct an object wave. As a rule, the reference wave has a simple and easily reproducible shape, for example, flat or spherical.

The term "diffractive medium" or "medium for recording (forming) a diffractive optical element" used in this document means a material carrier with certain physical properties, on the surface or in the volume of which a microstructure with a constant or variable period is formed.

The term "holographic medium" used in this document means an environment in which, by exposure to light, a change in some of its optical characteristics (transmittance, refractive index, or others) occurs, which remains in the environment for a sufficiently long time until the moment when this environment occurs recovering the recorded data, or for a longer time. A characteristic feature of the hologram recording medium is a high spatial resolution, which makes it possible to directly record interference patterns, which are holograms.

The term "very low recording threshold holographic medium" as used herein means a holographic medium whose properties begin to change even when it is irradiated with a weak low energy wave.

The term "thin holographic medium" used in this document means a holographic medium in which holographic optical elements are formed, when considering them, the effects associated with their finite thickness can be neglected...

The term "photosensitive waveguide" used in this document means a waveguide made of a material with such physical properties that a microstructure with a constant or variable period is formed on the surface or in the volume of the waveguide.

The term "space-time light modulator, PVMS" used in this document means a device that allows you to change the parameters of light radiation (amplitude, phase, polarization) in time and space.

The term "micromirror space-time light modulator, MPVMS" as used herein means a microelectromechanical system (MEMS) that creates an image of an array of microscopic mirrors with deflecting piezoelectric elements, with each mirror representing one pixel in the projected image.

The term "liquid crystal space-time light modulator, LCD PVMS" as used herein means a system based on transparent or reflective LCD microdisplays. LC PVMS modulates the amplitude or phase of light based on a change in the refractive index of the optical medium, for example, as a result of reorientation of liquid crystal molecules or as a result of phase transitions in liquid crystals.

The term "acousto-optic space-time light modulator, AO PVMS" as used herein means a device for deflecting a light beam due to its diffraction by a grating formed in glass as a result of spatial modulation of the refractive index by an acoustic wave. The principle of operation of AO PVMS is based on the diffraction of light by a traveling ultrasonic wave in an optically transparent material (glass). A traveling ultrasonic wave is created by a piezoelectric transducer attached to a glass plate. Due to the appearance of areas of compression and tension that appear in the glass and differ in the refractive index, a diffraction grating is formed in the medium. The light beam, diffracted by the grating, forms several output beams (diffraction orders), spaced apart in space at equal angles relative to each other. With the help of the aperture, the first maximum is selected from all output beams, which exists only in the presence of a sound wave in the modulator, and all the others are blocked.

The term "computer readable storage medium" as used herein means any means or group of means that can store data and / or instructions for a period of time. Computer-readable media may include, without limitation, storage media such as direct access storage (such as a hard disk drive or floppy disk), sequential access storage (such as magnetic tape), compact disc, CD -ROM, DVD, random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM) and / or flash memory; as well as communication media such as wires, optical fibers and other electromagnetic and / or optical media; and / or any combination of the above devices.

Next, referring to FIG. 2 will show the passage of an image 203 from a projector 202 to a user's eye in a virtual and augmented reality device 201 comprising a waveguide with holographic optical elements (206, 207, 208) according to an embodiment of the present invention.

In step (I), the original undistorted image 203 is input into the waveguide 204 from the image source 202 (projector) of the virtual and augmented reality device 201.

In step (II), the image is transmitted through the waveguide 204 with holographic optical elements 206, 207, 208. In contrast to the traditional approach, as the image is transmitted through the waveguide 204, aberrations caused by local structures formed by the waveguide 204 and fragments of the holographic medium are compensated for. which recorded holographic optical elements 206, 207, 208, due to the use of a waveguide with holographic optical elements 206, 207, 208, made according to the proposed in this application, the method.

For example, if a plane input wave 205 is applied to the input hologram optical element 206 of the waveguide 204 made according to the method proposed in this application, then the output hologram optical element 208 of the waveguide 204 will produce a plane output wave 209 that does not contain aberrations.

In step (III), a virtual image 210 free of aberrations is supplied from the waveguide 204 to the user's eye.

Thus, in a virtual and augmented reality device 201 comprising a waveguide 204 with holographic optical elements 206, 207, 208 according to the present invention, the post-processing step (IV) of the image that has passed through the waveguide structure is not required. In this case, the waveguide 204 according to the present invention is not ideal (i.e., it can be non-planar, non-uniform, contain defects that can cause aberrations of wave fronts propagating through it), in addition, fragments of one or more holographic media in which holographic optical elements 206, 207, 208 are also not ideal. Moreover, the virtual and augmented reality device is configured to input the original image 203 from the image source 102 into the waveguide 204, increase the geometric dimensions of the image and output a virtual image 210 free of aberrations from the waveguide 204 into the user's eye.

Thus, for the manufacture of virtual and augmented reality devices according to the present invention, commercial waveguides and standard holographic media can be used, which are not ideal in their properties and can introduce aberrations in wave fronts.

Next, referring to FIG. 3, a sequence of manufacturing a holographic optical element waveguide 204 in accordance with one embodiment of the present invention will be described.

A waveguide 204 is provided that may be flat or curved and may have aberrations, and as shown in FIG. 3 a), fix (fix) fragment (s) 212 'on it with one or more holographic media, which may also have aberrations. In this case, each fragment 212 'of the holographic medium is fixed at a certain place of the waveguide 204, depending on what general structure the waveguide 204 should have with this fragment 212' of the holographic medium, and what function the holographic optical element 212 recorded in this fragment should perform in the future. ... In fact, the location of fixation of each fragment 212 'of the holographic medium on the waveguide is determined by the design of the virtual and augmented reality device.

Further, as shown in FIG. 3 b), detection of aberrations created by the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium is performed using the inspection wave 313. In this case, the inspection wave can be plane, spherical, or have a specially selected wavefront shape. The specially selected shape of the wavefront of the inspection wave can be specified by means of traditional or diffractive optical elements, or using space-time light modulators, or a combination of both.

When detecting aberrations, the inspection wave 313 once passes the local structure formed by the waveguide 204 with its aberrations and the fragment 212 'of the holographic medium with its aberrations, and is distorted in accordance with the local aberrations of the waveguide 204 and the holographic medium 212'.

The inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 212' of the holographic medium, acquires aberrations. These aberrations of the inspection wave 313 'passing through the said local structure are detected by the wavefront detection and phase conjugation unit 314, the operation of which will be described in more detail below. Then, using the values of the phase and amplitude of the inspection wave obtained by the method of phase-shifting interferometry, in block 314, phase-conjugate aberrations to the aberrations of the inspection wave 313 'that have passed the said local structure are calculated, the obtained data is stored on a computer-readable storage medium for use in the next stage of the method.

As further shown in FIG. 3d) and 3 e), at the stage of detecting aberrations shown in Fig. 3 b), the inspection wave 313 can be applied at an arbitrary angle α to the surface of the waveguide 204.

An inspection wave 313, incident at an arbitrary angle α to the surface of the waveguide 204, passes through the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium, and acquires aberrations in accordance with a specific path through this local structure.

Thus, aberrations of the waveguide 204 and the fragment 212 'of the holographic medium are detected for inspection waves propagating at different angles α ₁ , α ₂ , ... α _n , through the local structure in which the hologram optical element 212 will be recorded and operated.

Measurements using the above-mentioned method of phase-shifting interferometry are based on the registration of several interferograms formed in the plane of the photodetector (for example, the CCD matrix of block 314) by two beams of light: undistorted (reference, reference) and distorted, which passed through the disturbing medium (a beam that acquired aberrations) ... The phase of the reference wave changes stepwise with a known phase shift, and the resulting interference fringes are processed by a computer using a special algorithm to obtain the desired distribution of the complex amplitude of the distorted wave.

Further, as shown in FIG. 3 c), by means of the unit 314 for detecting the wavefront and phase conjugation, the hologram optical element 212 is recorded in the fragment 212 'of the holographic medium, so as to compensate for the aberrations arising from the operation of the waveguide 204 with the fragment 212' of the holographic medium, due to the recording technology of this optical element ... For this, the obtained information about the distortions of the inspection wave 313 ', which has passed the local structure formed by the waveguide 204 and the fragment 212' of the holographic medium, is used when recording the holographic optical element 212 in the same fragment 212 'of the holographic medium. This is achieved by generating a predistorted object wave 315 'containing phase conjugate aberrations to aberrations of the inspection wave 313' that has passed the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium. The formation of the predistorted object wave 315 'can be achieved by supplying the object wave 315 to the wavefront detection and phase conjugation unit 314, where the object wave 315 can be predistorted using micromirror, liquid crystal or acousto-optic space-time light modulators (SPMM) according to the calculated phase conjugate aberrations.

When recording the holographic optical element 212 in the fragment 212 'of the holographic medium, a predistorted object wave 315' is used, containing the mentioned phase conjugate aberrations, and an undistorted reference wave 316, which can have a plane, spherical shape or a specially selected wavefront shape. In this case, a specially selected shape of the wavefront of the reference wave can be set by means of traditional or diffractive optical elements, or by means of space-time light modulators, or their combination. During recording, as well as during further operation of the waveguide 204, each fragment 212 'of the holographic medium must remain fixed in the same place on the waveguide 204 as at the stage of detecting aberrations. If this condition is met, the phase-conjugate aberrations will compensate for the aberrations arising from the passage of the object wave 315 along the same optical path that was used to detect the aberrations of the inspection wave 313 'that passed the local structure formed by the waveguide 204 and the fragment 212' of the holographic medium, and when recording the holographic optical element 212 in the fragment 212 'of the holographic medium. Thus, the present invention provides a method for manufacturing a waveguide with holographic optical elements, in which the ability to correct aberrations is provided at the manufacturing stage.

FIG. 3 e) shows a set of recorded holographic optical elements 212 fixed on a section of waveguide 204, and fragments of one or more holographic media can be used to record holographic optical elements 212, for example, fragments of two different holographic media.

FIG. 4, embodiments of the wavefront detection and phase conjugation unit 314 for implementing the method for manufacturing a waveguide with holographic optical elements according to the present invention are illustrated. Block 314 can be implemented as a single block combining two functions: wavefront detection and phase conjugation, or can be implemented as separate sub-blocks, each of which performs its own function.

FIG. 4 a) is a schematic illustration of an embodiment of a wavefront detection and phase conjugation unit 314 comprising a Shack-Hartmann wavefront sensor 417, a computerized controller 418, and a space-time light modulator (SPMM) 419.

The wavefront and phase conjugation unit 314 operates as follows.

The inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 212' of the holographic medium, is detected by the Shack-Hartmann wavefront sensor 417, then the phase-conjugate aberrations to the aberrations of the inspection wave 313 'that have passed the local structure are calculated by the computerized controller 418 formed by the waveguide 204 and the fragment 212 'of the holographic medium. Then, using the plane object wave 315 and the calculated phase-conjugate aberrations, a predistorted object wave 315 'is formed, containing the phase-conjugate aberrations to the detected aberrations of the inspection wave 313', which has passed the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium. The formation of the predistorted object wave 315 'is carried out by means of the PMS 419.

FIG. 4 b) schematically shows another embodiment of a wavefront and phase conjugation unit 314 comprising a computerized control device 418, a space-time light modulator (SPM) 419, an electro-optical modulator (EO) 420, a CCD matrix 421, and a beam splitter 422.

The wavefront and phase conjugation unit 314 operates as follows.

The inspection wave 313 and the inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 212' of the holographic medium, form an interference pattern in the plane of the CCD matrix 421. In this case, the inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium is directed towards the CCD matrix 421 by means of a beam splitter 422. The relative phase between the inspection waves 313 and 313' is controlled by an electro-optical modulator (EO) 420. In this case, the amplitude and phase of the inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the holographic medium fragment 212 can be uniquely identified using the phase-shifting interferometry method described above. Then, by means of the computerized controller 418, the phase conjugate aberrations to the aberrations of the inspection wave 313 'are calculated. Then, using the divider 422, the plane object wave 315 is fed to the space-time light modulator 419, by means of which, using the calculated phase-conjugate aberrations, a predistorted object wave 315 'is formed, containing the phase-conjugate aberrations to the detected aberrations of the inspection wave 313' that has passed the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium.

FIG. 4 c) schematically shows an embodiment of the wavefront detection and phase conjugation unit 314, containing a computerized control device 418, a space-time light modulator (SPMM) 419, a high-resolution CMOS matrix 423, a phase LC PMS 424 and a processor 425. Sharing the LCD The 424 PVMS, 423 CMOS and 425 processor provide more than 100-fold improvement in spatial resolution compared to the Shack-Hartmann sensor.

In this case, block 314 operates as follows. The inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 212 of the holographic medium, is fed to the LC PMS 424. The LC PMS 424 modulates the supplied wave using several randomly specified templates, and the intensity of the wave transmitted through the LC PMS 424 is measured using CMOS Arrays 423. The resulting data is then processed by a processor 425 using a computational phase search algorithm that calculates the complex amplitude of the inspection wave 313 'incident on the CMOS Array 423. The computerized controller 418 then calculates the phase conjugate aberrations to the aberrations of the inspection wave 313 'that has passed the local structure. Then, using the plane object wave 315 and the calculated phase-conjugate aberrations, a predistorted object wave 315 'is formed, containing the phase-conjugate aberrations to the detected aberrations of the inspection wave 313', which has passed the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium. The formation of the predistorted object wave 315 'is provided by the space-time light modulator 419.

Thus, when recording the holographic optical element 212, the aberrations possessed by the waveguide 204 and the fragment 212 'of the holographic medium are taken into account with the opposite sign.

All fragments 212 'of the holographic medium that are to be used to create a waveguide structure for the intended virtual and augmented reality device 201 can be recorded in a similar way and placed in the corresponding regions of the waveguide.

The number and structure of the hologram optical elements 212 are not limited to the configuration shown in FIG. 3, and may vary depending on the architecture of the virtual and augmented reality device. Holographic optical elements 212 recorded in fragments of one holographic medium can be used, or holographic optical elements 212 recorded in fragments of different holographic media can be used.

Moreover, each of the holographic optical elements 212 must be recorded in compliance with the proposed technology, i.e. with detecting predistortion and introducing this predistortion into the recordable hologram optical element 212 during the recording step.

With this approach, each holographic optical element 212 can perform a double function: deflection and / or direction of waves propagating along the waveguide, and, at the same time, compensation for aberrations caused by the local structure formed by the waveguide 204 and the fragment 212 'of the holographic medium in which the optical element is recorded 212. In addition, the hologram optical element 212 can be configured as a transmissive or reflective hologram element. For example, when recorded as a transmissive hologram element, the hologram optical element 212 will convert the incident optical radiation as it passes through the element, while being recorded as a reflective hologram element, the hologram optical element 212 will convert the incident optical radiation as it is reflected from this element.

Thanks to this combination of functions, it is possible to manufacture a waveguide that allows maintaining the quality during image transmission and creating a more compact and cheaper design of a virtual and augmented reality device, since in this case imperfect holographic media and waveguides can be used, eliminating the need for additional components of the device that implement or post-processing of images.

The following materials can be used as holographic media: photopolymers, photothermoplastics, photochromic materials, photothermorefractive materials, photoresists, silver halide photographic materials, or dichromated gelatin. Moreover, a fragment of a holographic medium can have the form of a film or a layer of a given thickness and geometric shape. Thickness and geometric shape may vary depending on the architecture of the virtual and augmented reality device.

Glassy, glass-ceramic, crystalline, polymer and other media can be used that have sufficient transmission of light in the visible region of the spectrum and the possibility of forming microstructures in them with a constant or varying period according to a given law, so that light diffraction can be carried out on these structures, and that these microstructures were preserved in the medium for a long (preferably infinite) time. Media can be sprayed films / layers, grown films / layers; films / layers planted on optical contact; glued films / layers.

An embodiment of the present invention provides a method for manufacturing a holographic optical element waveguide using a photosensitive waveguide.

This case is different from the case shown in FIG. 3 by the fact that it is not required to use fragments of one or more holographic media and, accordingly, to fix them on the waveguide, since holographic optical elements are recorded directly in the waveguide itself. With regard to the implementation of the remaining operations, they are carried out in the same way as described above with reference to FIG. 3, 4.

As shown in FIG. 5 a), this method provides a photosensitive waveguide 504 that can be flat or curved and can have aberrations.

Using the inspection wave 513, local aberrations of the photosensitive waveguide 504 are detected, for which the aberrations of the inspection wave 513 ', passed through the local structure of the waveguide 504, in which the hologram optical element 512 will be recorded, are detected using the wavefront detection and phase conjugation unit 314, and the phase -conjugate aberrations.

As shown in FIG. 5 b), the hologram optical element 512 is recorded directly in the photosensitive waveguide 504 using a predistorted object wave 515 'containing the mentioned phase conjugate aberrations and a reference wave 516. In this case, as shown in FIG. 5 b) and 5 c), each hologram optical element 512 must be recorded in the same local structure 526 of the waveguide 504, for which the aberration of the inspection wave 513 'passed through this local structure was detected. The number and structure of the holographic optical elements 512 are not limited and may vary depending on the architecture of the virtual and augmented reality device.

The waveguide 504 itself can be made of a photosensitive material in which a holographic optical element can be formed. For example, it can be a crystalline material (photochromic or photothermorefractive crystal, etc.), glass (photochromic or photothermorefractive glass, etc.), glass ceramics, photopolymer material (PMMA and other photopolymers.). Thus, in this case, it is not required to apply the holographic medium to the waveguide 504 itself, since it plays the role of both a structural element and is a holographic medium.

In an embodiment, a method is provided for manufacturing a waveguide with holographic optical elements based on very low recording threshold holographic media. Examples of such environments are, for example, photothermorefractive crystals, photochromic materials, silver halide photographic materials, dichromated gelatin.

In this case, the use of the inspection wave at the stage of detecting aberrations of the local structure formed by the waveguide and a fragment of the holographic medium becomes impossible, since the use of even a weak low-energy wave can lead to the illumination of the holographic medium used to record the holographic optical element.

As shown in FIG. 6 a), b), when implementing this method, a waveguide 604 is provided, which can be flat or curved and can have aberrations. In this case, the inspection wave is not used. Local aberrations of waveguide 604 are detected using a flat object wave 615, for which the unit 314 for detecting the wavefront and phase conjugation detects aberrations of the object 615 ', passed through the local structure of the waveguide 604, which is additionally shown in FIG. 6b) as region 626), and the phase-conjugate aberrations are calculated.

Then, the holographic optical element 612 is recorded in a fragment of the holographic medium with a very low recording threshold using a predistorted object wave 615 '' containing the aforementioned phase conjugate aberrations and a reference wave 616. Further, the hologram optical element 612 recorded in the fragment of the holographic medium should be fixed on the same region 626 of the waveguide 604 for which the aberration was detected with the object wave 615. in contrast to the case shown in FIG. 3, when a fragment of the holographic medium is previously fixed on the waveguide, in this case, the fixation of the fragments of the medium to the waveguide is carried out after the holographic optical element 612 is recorded in the corresponding fragment of the holographic medium. The number and structure of the holographic optical elements 612 are not limited and may vary depending on the architecture of the virtual and augmented reality device. Holographic optical elements 612 recorded in fragments of the same holographic medium can be used, or fragments of different holographic media can be used.

With regard to the operations of generating the predistorted wave 615 '' and recording the hologram optical element 612, they are performed in the same way as described above with reference to FIG. 3, 4.

FIG. 7 schematically shows a waveguide with holographic optical elements, manufactured by the method described, for example, in relation to FIG. 3.

Waveguide 704 contains holographic optical elements 706, 707, 708 fixed on it, recorded in corresponding fragments of holographic media. Moreover, the hologram optical element 706 is an input hologram optical element for inputting an image into the waveguide 704, the hologram optical element 707 is a multiplying hologram optical element made with the possibility of increasing the geometric dimensions of the transmitted image, the hologram optical element 708 is an output hologram optical element for outputting an image from the waveguide ... The number and structure of the hologram optical elements 706, 707, 708 are not limited to the configuration shown in FIG. 7, and may vary depending on the architecture of the virtual and augmented reality device 201.

The waveguide according to the present invention operates in a virtual and augmented reality device 201 as follows.

The original undistorted image 703 is input into the waveguide 704 from the image projector 202 of the virtual and augmented reality device 201 through one or more hologram input optical elements 706.

When the image passes through the local structures formed by the waveguide and fragments of the holographic media in which the holographic optical elements 706, 707, 708 are recorded, the aberrations caused by these local structures are compensated.

In particular, this is shown by the example of the propagation of the wavefront 727, reconstructed by the hologram optical element 706. The wavefront 727 has aberrations that are phase conjugated with aberrations introduced by the local structure formed by the waveguide 704 and a fragment of the holographic medium in which the hologram optical element 706 is recorded, and follows the same optical path through this local structure as when recording the hologram optical element 706.

Phase-conjugate and phase-non-conjugate aberrations cancel each other out as the wavefront 727 propagates through the waveguide. Therefore, the resulting reconstructed wave 727 'does not contain aberrations.

This aberration compensation approach can be used for any number of holographic optical elements fixed to the waveguide 704, and thus an aberration-free image 710 can be output from the waveguide to the user's eye.

This is further illustrated by the example of the passage of the read wave 728 through the hologram optical element 706, which is recorded with the possibility of compensating for aberrations introduced by the local structure formed by the waveguide 704 and the corresponding fragment of the holographic medium in which the hologram optical element 706 is recorded. structure, does not contain aberrations.

When a waveguide with holographic optical elements is used as part of a virtual and augmented reality device according to the present invention, the waveguide is illuminated with a readout wave 728 having the same wavelength that was used when recording the holographic optical elements.

In this case, the wavefront reconstructed by holographic optical elements has aberrations that are phase conjugated with aberrations of local structures formed by the waveguide and fragments of holographic media, and follows the same optical path through the waveguide and holographic medium, which have aberrations, which was used for recording. since with this propagation through the waveguide, the phase-conjugate and non-conjugate aberrations cancel each other out.

This can be illustrated in a fairly simple way.

Let the spatially varying amplitude transmittanceτ(x, y) a waveguide and a fragment of a holographic medium with aberrations is equal to:

τ ( x, y ) = exp ( jφ ( x, y )) ,

where φ ( x, y ) is the phase shift, which is a random function of the position with coordinates x , y in the plane perpendicular to the direction of propagation of the wave front through the waveguide and a fragment of the holographic medium that have aberrations;

where x is the coordinate in the Cartesian coordinate system in the plane perpendicular to the direction of propagation of the wave front through the waveguide and a fragment of the holographic medium with aberrations;

where y is the second coordinate in the Cartesian coordinate system in the plane perpendicular to the direction of propagation of the wave front through the waveguide and a fragment of the holographic medium with aberrations;

j is the imaginary unit.

A hologram optical element recorded by a predistorted object wave containing phase-conjugate aberrations to the aberrations of the inspection wave detected after the inspection wave has passed the local structure formed by the waveguide and a fragment of the holographic medium and an undistorted reference wave has an amplitude transmittance equal to τ * (x , y) , where the asterisk denotes complex conjugation. When reading the hologram optical element, the illuminating object from the image projector has a complex amplitude distribution A (x, y) in the plane of the hologram optical element. After passing through a holographic optical element recorded in a fragment of a holographic medium, and then through a waveguide with aberrations, the distribution of light diffracted on the holographic optical element occurs as follows:

τ * (x, y) τ (x, y) A (x, y) = A (x, y).

Therefore, the image of the object after passing through a fragment of the holographic medium and the waveguide with aberrations should not contain distortions. If all the holographic optical elements fixed on the waveguide are recorded in a similar way and take into account the aberrations introduced by the mentioned local structures and the waveguide, then the resulting output virtual image will be free of aberrations due to the elimination of aberrations of the waveguide and the holographic medium.

In addition, with reference to FIG. 8, the case of aberration compensation when using a thin holographic medium will be discussed, which relates to an embodiment of a method for manufacturing a waveguide with holographic optical elements.

In the case of a thin holographic medium, it is possible not to pre-distort the object wave containing phase-conjugate aberrations and immediately record the distortions caused by the local structure of the waveguide in the form of a holographic optical element, while in the fragment of the thin holographic medium only aberrations from the waveguide are recorded, and the phase pairing fails. The present version is based on the fact that the phase-conjugate function of waveguide aberrations is directly recorded in the hologram optical element during its formation, and when the wavefront that reads the hologram optical element passes through the same region of the waveguide with aberrations, they are compensated. But this option is possible only for the case of recording a holographic optical element in a fragment of a thin holographic medium. This is due to the fact that during the diffraction of optical radiation on a holographic optical element recorded in a fragment in a thin holographic medium, at least several reconstructed waves are formed (minus the first order, zero and first diffraction orders), one of which contains information about the phase conjugate function waveguide aberrations. Thus, the phase-conjugate function of waveguide aberrations will be present in the recorded hologram optical element when the reading wavefront passes through it, due to which the aberrations caused by the corresponding local structure of the waveguide, for which the recording was performed using the object wave that passed this local waveguide structure.

It can be shown mathematically that one of the waves reconstructed from a holographic optical element recorded in a fragment of a thin holographic medium will indeed contain an undistorted complex amplitude distribution of the image passed through the aberrated waveguide.

At the stage of recording (I) of a holographic optical element in a fragment of a thin holographic medium, an undistorted plane object wave 815 passes through the local structure of the waveguide 804 with aberrations (where the aberrations are described by the phase aberration function of the waveguide Φ ( x, y )), as a result of this , it acquires aberrations according to aberrations waveguide 804, and is mapped into the plane of the recording holographic optical element 812, where it interferes with the off-axis plane reference wave 816 ( R ( x, y )).

Let the spatially varying function of the phase aberration of the waveguide with aberrations Φ ( x, y ) be equal to:

Φ ( x, y ) = exp ( jφ ( x, y )) ,

where φ ( x, y ) is the phase shift, which is a random function of the position with coordinates x , y in the plane perpendicular to the direction of propagation of the wave front through the waveguide with aberrations;

where x is the coordinate in the Cartesian coordinate system in the plane perpendicular to the direction of propagation of the wave front through the waveguide with aberrations;

where y is the second coordinate in the Cartesian coordinate system in a plane perpendicular to the direction of propagation of the wave front through, which has aberrations;

j is the imaginary unit.

The amplitude of the reference wave 816 (R(x, y)) is given as:

R(x, y) = exp (j2πγy),

where γ = sinα / λ,

α is the angle in the y direction between two recording beams,

λ -wavelength recording a hologram optical element of radiation.

The resulting intensity of the interference pattern in the plane of the recorded hologram optical element 812 is described as follows:

.

...

,Suppose that the transmission H ( x, y ) of the hologram optical element 812 is proportional to the exposure intensity:

,

where κ is the coefficient of proportionality.

, а после прохождения голограммного оптического элемента 812 равно:When reading (II) the hologram optical element 812 during the operation of the augmented and virtual reality device, the reading wave 828 from the image projector, having a complex amplitude distribution A ' ( x, y ) in the plane of the waveguide 804, passes through the local structure of the waveguide 804, which has aberrations, to hologram optical element 812. The amplitude distribution of the read wave 828 in the plane of the hologram optical element 812 is equal to

, and after passing through the hologram optical element 812 is equal to:

.

...

. Принимая во внимание вид функции пропускания H(x, y) голограммного оптического элемента 812 получаем:Three diffracted waves occur after holographic optical element 812, two of which (829 and 830) are shown in FIG. 8. We are interested in the diffracted wave 830, which contains the phase conjugate function of waveguide aberrations

... Taking into account the form of the transmission function H ( x, y ) of the hologram optical element 812, we obtain:

,

,

those. in the diffracted wave 830, propagating in the direction of the reference wave 816 used in the recording, we get an undistorted image of the object.

Next, referring to FIG. 2, 7, a method of operation of a virtual and augmented reality device containing a waveguide with holographic optical elements according to the present invention will be described.

In the first step of the method, the original image 203 is fed into a waveguide 204 with holographic optical elements 206, 207, 208 (706, 707, 708) from an image source 202.

At the second stage of the method, an image 203 is transmitted through a waveguide 204 with hologram optical elements 206, 207, 208 (706, 707, 708) with compensation for aberrations caused by local structures formed by the waveguide 204 and fragments of the holographic medium in which the holographic optical elements 206 are recorded, 207, 208 (706, 707, 708).

At the third stage of the method, a virtual image 210 free of aberrations is output from the waveguide with holographic optical elements 206, 207, 208 (706, 707, 708) into the user's eye.

The method may further comprise increasing the geometric dimensions of the image in the process of transmitting the image through the waveguide 204 with holographic optical elements 206, 207, 208 (706, 707, 708).

In general, the operation of virtual and augmented reality devices is possible not only with waveguides equipped with holographic optical elements (HOE), but also with waveguides equipped with diffractive optical elements (DOE), as well as in a mixed configuration, when both types of elements are used together in the device. ... In this case, the following should be noted.

The term "diffractive optical element" covers a wide class of optical elements, one of the special cases of which is "holographic optical elements". At the same time, among the diffractive optical elements, it is possible to additionally single out the types of elements that, under certain conditions of their recording, will also be able to perform a dual role in a virtual and augmented reality device - to work as elements for redirecting waves in a waveguide, and to correct local aberrations as these waves are transmitted. along the waveguide. In particular, this applies to diffractive optical elements based on diffractive structures on photoresists and diffractive structures in chalcogenide materials. Diffractive media based on structures in these materials are recordable and diffractive optical elements can be recorded therein according to the method of the present invention.

Both types of elements (HOE and DOE) can be simultaneously fixed on the waveguide of a virtual and augmented reality device, which will perform the same functions when converting transmitted (reflected) optical radiation, while the location of hologram and diffractive optical elements on the waveguide in a certain configuration will allow to take into account in the design of a virtual and augmented reality device the higher diffraction efficiency of diffractive optical elements (that is, a higher intensity of diffracted radiation) or their ability to better match (in spectrum and angular characteristics) with the radiation source (projector).

Methods for manufacturing a waveguide with the aforementioned types of diffractive optical elements or a waveguide in a mixed configuration of diffractive and holographic optical elements are similar to the method described above for producing waveguides with holographic optical elements.

Next, referring to FIG. 9, a sequence will be described for manufacturing a diffractive optical element waveguide 204 according to an embodiment of the present invention, wherein the diffractive optical elements are writeable diffractive optical elements based on diffractive structures on photoresists, diffractive structures in chalcogenide materials.

A waveguide 204 is provided that may be flat or curved and may have aberrations, and as shown in FIG. 9 a), fix (fix) fragment (s) 912 'on it with one or more recorded diffraction media (or media for recording (forming) DOE). The one or more recordable diffractive media may include diffractive structures on photoresists and diffractive structures on chalcogenide materials.

Further, as shown in FIG. 9 b), detection of aberrations created by the local structure formed by the waveguide 204 and the fragment 912 'of the recorded diffraction medium is performed using the inspection wave 313. In this case, the inspection wave can be plane, spherical, or have a specially selected wavefront shape.

When detecting aberrations, the inspection wave 313 once passes the local structure formed by the waveguide 204 with its aberrations and the fragment 912 'of the recorded diffractive medium with its aberrations, and is distorted in accordance with the local aberrations of the waveguide 204 and the fragment 912' of the recorded diffractive medium. Moreover, as shown additionally in FIG. 3d) and 3 e), the inspection wave 313 can be applied at an arbitrary angle α to the surface of the waveguide 204.

The inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 912' of the recorded diffractive medium, acquires aberrations, which are detected by the wavefront and phase conjugation unit 314, the operation of which is described in detail above. Then, using the phase and amplitude values of the inspection wave obtained by the phase-shifting interferometry method in block 314, the phase-conjugate aberrations to the aberrations of the inspection wave 313 'that have passed the local structure are calculated.

When recording a diffractive optical element 912 in a fragment 912 'of the recorded diffractive medium, a predistorted object wave 315' is used, containing the mentioned phase conjugate aberrations, and an undistorted reference wave 316, which can have a plane, spherical or specially selected wavefront shape. During recording, as well as during further operation of the waveguide 204, each fragment 912 'of the recorded diffractive medium must remain fixed in the same place on the waveguide 204 as at the stage of detecting aberrations. If this condition is met, the phase-conjugate aberrations will compensate for the aberrations arising from the passage of the object wave 315 along the same optical path that was used to detect the aberrations of the inspection wave 313 ', which passed the local structure formed by the waveguide 204 and the fragment 912' of the recorded diffractive medium. and also for recording the diffractive optical element 912 in the fragment 912 'of the recorded diffractive medium.

When recording on the surface or in the volume of the above fragments 912 'of the recorded diffraction medium using optical radiation, microstructures with a constant or with a period varying according to a given law are formed.

FIG. 9 e) shows a set of recorded diffractive optical elements 912 fixed on a portion of the waveguide 204, and fragments of different recording media can be used to record the diffractive optical elements 912.

The manufacturing sequence of waveguide 204 in a mixed configuration, when both types of elements (holographic and diffractive) are used together in the device, differs from the sequence depicted in FIG. 9, only in that fragments of one or more recorded diffraction media are recorded on the waveguide. The one or more recordable diffractive media may include diffractive structures on photoresists and diffractive structures on chalcogenide materials. Accordingly, when recording in a diffractive structure on photoresists or in a diffractive structure, a diffractive optical element will be formed in chalcogenide materials; when recording in a holographic medium, a holographic optical element will be formed.

Otherwise, the same sequence of actions is performed as described above with reference to FIG. 3, 4 and 9.

Next, referring to FIG. 10, the sequence of manufacturing the waveguide 204 in this mixed configuration will be briefly described.

A waveguide 204 is provided that may be flat or curved and may have aberrations, and as shown in FIG. 10 a), the fragment (s) 1012 'of one or more recordable diffractive media, which may include diffractive structures on photoresists, diffractive structures in chalcogenide materials, and holographic media, are fixed (fixed) thereon.

Further, as shown in FIG. 10 b), detection of aberrations created by the local structure formed by the waveguide 204 and the fragment 1012 'of the recorded diffraction medium is performed using the inspection wave 313. Then, using the phase and amplitude values of the inspection wave obtained by the phase-shifting interferometry method in block 314, phase-conjugate aberrations to aberrations of the inspection wave 313 'are calculated, which has passed the local structure formed by the waveguide 204 and the fragment 1012' of the recorded diffractive medium.

The aberrations of the inspection wave 313 ', having passed the local structure formed by the waveguide 204 and the fragment 1012' of the recorded diffractive medium, are detected by the wavefront and phase conjugation unit 314, the operation of which is described in detail above. Then, using the values of the phase and amplitude of the inspection wave obtained by the phase-shifting interferometry method in block 314, phase-conjugate aberrations to the aberrations of the inspection wave 313 'passed through the local structure formed by the waveguide 204 and the fragment 1012' of the recorded diffractive medium are calculated.

When recording a diffractive optical element 1012 in a fragment 1012 'of the recorded diffractive medium, a predistorted object wave 315' containing the corresponding phase conjugate aberrations and an undistorted reference wave 316 are used. of the medium must remain fixed in the same place on the waveguide 204 as in the aberration detection step.

Image transmission in a virtual and augmented reality device comprising a diffractive optical element waveguide 1012 occurs in the same manner as described with reference to FIG. 2, 7 for an augmented reality device containing a waveguide with holographic optical elements.

FIG. 11 is a schematic diagram of a virtual and augmented reality device comprising a diffractive optical element waveguide fabricated in the manner described above with reference to FIG. ten.

Waveguide 204 contains fixed on it diffractive optical elements 1106, 1107, 1108, recorded in the corresponding fragments of the recorded diffractive media. Moreover, the diffractive optical element 1106 is an input diffractive optical element for inputting an image into the waveguide 204, the diffractive optical element 1107 is a multiplying diffractive optical element made with the possibility of increasing the geometric dimensions of the transmitted image, the diffractive optical element 1108 is an output diffractive optical element for outputting an image from the waveguide 204. The number and structure of the diffractive optical elements 1106, 1107, 1108 are not limited to the configuration shown in FIG. 11, and may vary depending on the architecture of the virtual and augmented reality device 201.

The waveguide according to the present invention operates in a virtual and augmented reality device 201 as follows.

The original undistorted image 203 is input into the waveguide 204 from the image projector 202 of the virtual and augmented reality device 201 through one or more input diffractive optical elements 1106.

When the image 203 passes through the local structures formed by the waveguide and fragments of the recorded diffractive media, in which the diffractive optical elements 1106, 1107, 1108 are recorded, the aberrations caused by these local structures are compensated.

For example, if a plane input wave 1105 is applied to the input diffractive optical element 1106 of the waveguide 204 made according to the method proposed in this application, then the output diffractive optical element 1108 of the waveguide 204 will produce a plane output wave 1109 that does not contain aberrations.

Next, a virtual image 210 free of aberrations is supplied from the waveguide 204 to the user's eye.

The method of operation of a virtual and augmented reality device containing a waveguide with diffractive optical elements is similar to the method of operation of a virtual and augmented reality device containing a waveguide with holographic optical elements described above with reference to FIG. 2, 7.

In the first step of the method, the original image 203 is supplied to the waveguide 204 with diffractive optical elements 1106, 1107, 1108 from the image source 202.

At the second stage of the method, an image is transmitted through a waveguide 1104 with diffractive optical elements 1106, 1107, 1108 with compensation for aberrations caused by local structures formed by the waveguide 204 and fragments of the recorded diffractive media, in which the diffractive optical elements 1106, 1107, 1108 are recorded.

In the third step of the method, a virtual image 210 free of aberrations is output from the waveguide 204 with diffractive optical elements 1106, 1107, 1108 into the user's eye.

The method may further comprise increasing the geometric dimensions of the image in the process of transmitting the image through the waveguide 1104 with diffractive optical elements 1106, 1107, 1108.

It should be noted that embodiments of the invention have been described with reference to various objects. However, one of ordinary skill in the art will understand from the above and the following description that, unless otherwise indicated, in addition to any combination of features related to one type of object, any combination of features related to different objects is also considered disclosed in this application. However, all features can be combined to provide synergistic effects that are more than a simple sum of features.

Although the invention has been illustrated in the drawings and described in detail in the foregoing description, these drawings and description are to be considered as illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Specialists in the art will be able to envisage and practice other variations of the disclosed embodiments as a result of examination of the drawings, the disclosure and the dependent claims.

In the claims, the word “comprising” does not exclude other elements or components, and the singular does not exclude the plural. The mere fact that some measures are mentioned in mutually different dependent claims does not mean that a combination of these measures cannot be used to their advantage. Any reference designations in the claims should not be construed as limiting their scope.

Claims (75)

1. A method of manufacturing a waveguide with diffractive optical elements, comprising: - providing a waveguide; - fixation on the waveguide of fragments of one or more holographic environments; - recording in each fragment of the holographic environment a diffractive optical element, which is a holographic optical element, using a predistorted object wave containing phase-conjugate aberrations to the aberrations of the inspection wave detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the holographic medium. 2. The method according to claim 1, wherein the inspection wave is passed through each local structure formed by the waveguide and a fragment of the holographic medium. 3. A method according to claim 1 or 2, wherein the aberrations of the inspection wave that have passed the local structure formed by the waveguide and a fragment of the holographic medium are detected using a Shack-Hartmann wavefront sensor, a CCD or CMOS matrix. 4. A method according to any one of claims. 1-3, wherein the phase-conjugate aberrations are calculated using the phase and amplitude values of the inspection wave obtained by the phase-shifting interferometry method. 5. The method of claim 4, wherein after the calculation, the phase conjugate local aberrations are stored on a computer-readable storage medium. 6. The method according to any one of claims. 1-5, where the predistorted object wave is generated by distorting the object wave by means of micromirror, liquid crystal or acousto-optic space-time light modulators based on the calculated phase-conjugate aberrations. 7. A method according to any one of claims. 1-6, wherein the recording of the diffractive optical element is performed with a predistorted object wave and an undistorted reference wave . 8. The method according to any one of claims. 1-7, and the phase-conjugate aberrations compensate for the aberrations arising from the passage of the object wave along the same optical path that was used to detect aberrations by the inspection wave that passed the local structure formed by the waveguide and a fragment of the holographic medium, and to record the diffractive optical element in fragment of the holographic environment. 9. A method according to any one of claims. 1-8, with holographic media include photopolymers, photothermoplastics, photochromic materials, photothermorefractive materials, photoresists, silver halide photographic materials, or dichromated gelatin. 10. The method according to any one of claims. 1-9, and the fragment of the holographic medium has the form of a film or layer of a given thickness and geometric shape. 11. The method according to any one of claims. 1-10, each diffractive optical element being recorded so that it deflects and / or guides waves propagating along the waveguide and compensates for aberrations caused by the local structure formed by the waveguide and a fragment of the holographic medium in which the optical element is recorded. 12. The method according to any one of claims. 1-11, wherein the diffractive optical element is a transmissive or reflective diffractive element. 13. The method according to any one of claims. 1-12, where the inspection wave is plane or spherical or has a specially selected wavefront shape, moreover, the reference wave is plane or spherical, or has a specially selected wavefront shape. 14. The method according to any one of claims. 1-13, wherein the inspection wave is fed at an arbitrary angle to the surface of the waveguide. 15. The method according to any one of claims. 1-14, wherein the predistorted object wave is supplied at an arbitrary angle to the waveguide surface when recording the diffractive optical element, and the angle of incidence of the predistorted object wave on the waveguide surface is equal to the angle of incidence of the inspection wave on the waveguide surface when aberrations are detected. 16. The method according to any one of paragraphs. 1-15, each of said diffractive optical elements being fixed to the waveguide at a predetermined location. 17. The method according to any one of paragraphs. 1-16, wherein the waveguide and fragments of said one or more holographic media may have defects that cause aberrations when waves propagate through them. 18. The method according to any one of claims. 1-17, wherein the waveguide is flat or curved. 19. Waveguide with diffractive optical elements, made by the method according to any one of paragraphs. 1-18, wherein the diffractive optical elements are holographic optical elements. 20. A waveguide according to claim 19, wherein said diffractive optical elements comprise: one or more input diffractive optical elements for inputting an image into the waveguide, one or more multiplying diffractive optical elements made with the possibility of increasing the geometric dimensions of the transmitted image, and one or more output diffractive optical elements for outputting an image from the waveguide. 21. A virtual and augmented reality device comprising a waveguide with diffractive optical elements according to any one of claims 19 to 20, wherein the diffractive optical elements are holographic optical elements. 22. The device according to claim 21, configured to input the original image from the image source into the waveguide with diffractive optical elements, increase the geometric dimensions of the image and output a virtual image free from aberrations from the waveguide with holographic optical elements into the user's eye. 23. A device according to claim 21 or 22, configured to compensate for aberrations caused by local structures of a waveguide with diffractive optical elements when transmitting an image through a waveguide with diffractive optical elements. 24. Device according to any one of paragraphs. 21-23, and the source of the image is a projector. 25. A method of operation of a virtual and augmented reality device containing a waveguide with diffractive optical elements, according to any one of claims. 21-24, and the method contains: - supply of the original image to the waveguide with diffractive optical elements, which are holographic optical elements, from the image source, - image transmission through a waveguide with diffractive optical elements with compensation for aberrations caused by local structures of a waveguide with diffractive optical elements, - output of a virtual image, free from aberrations, from a waveguide with diffractive optical elements into the user's eye. 26. The method according to claim 25, comprising increasing the geometric dimensions of the image in the process of image transmission through a waveguide with diffractive optical elements... 27. A method for manufacturing a waveguide with diffractive optical elements, comprising: - providing a waveguide, - fixation on the waveguide of fragments of one or more recorded diffraction media, - recording in each fragment of the recorded diffraction medium a diffractive optical element using a predistorted object wave containing phase conjugate aberrations to the aberrations of the inspection wave detected after the inspection wave passes the local structure formed by the waveguide and this fragment of the recorded diffractive medium. 28. The method of claim 29, wherein the recording diffractive media includes diffractive structures and holographic media. 29. The method of claim 27 or 28, wherein said diffractive structures include diffractive structures on photoresists and diffractive structures in chalcogenide materials. 30. The method according to claim 28, wherein the holographic media include photopolymers, photothermoplastics, photochromic materials, photothermorefractive materials, photoresists, silver halide photographic materials, or dichromated gelatin. 31. The method according to any of paragraphs. 27-30, wherein the inspection wave is passed through each local structure formed by the waveguide and the fragment of the recorded diffractive medium. 32. The method according to any one of paragraphs. 27-31, wherein the aberrations of the inspection wave that have passed the local structure formed by the waveguide and a fragment of the recorded diffractive medium are detected using a Shack-Hartmann wavefront sensor, a CCD or CMOS matrix. 33. The method according to any one of paragraphs. 27-32, wherein the phase conjugate aberrations are calculated using the phase and amplitude values of the inspection wave obtained by phase shifting interferometry. 34. The method of claim 33, wherein after the calculation, the phase conjugate local aberrations are stored on a computer-readable storage medium. 35. The method according to any one of paragraphs. 27-34, where the predistorted object wave is generated by distorting the object wave by means of micromirror, liquid crystal or acousto-optic space-time light modulators based on the calculated phase-conjugate aberrations. 36. The method according to any one of paragraphs. 27-35, wherein the recording of the diffractive optical element is performed with a predistorted object wave and an undistorted reference wave . 37. The method according to any one of paragraphs. 27-36, and the phase-conjugate aberrations compensate for the aberrations arising during the passage of the object wave along the same optical path that was used in the detection of aberrations by the inspection wave that passed the local structure formed by the waveguide and a fragment of the recorded diffractive medium, and when recording a diffractive optical element in a fragment of the recorded diffraction medium. 38. The method according to any one of paragraphs. 27-37, and the fragment of the recorded diffraction medium has the form of a film or layer of a given thickness and geometric shape. 39. The method according to any one of paragraphs. 27-38, each diffractive optical element being recorded so that it deflects and / or guides waves propagating through the waveguide and compensates for aberrations caused by the local structure formed by the waveguide and a fragment of the recorded diffractive medium in which the optical element is recorded. 40. The method according to any one of paragraphs. 27-39, wherein the diffractive optical element is a transmissive or reflective diffractive element. 41. The method according to any one of paragraphs. 27-40, and the inspection wave is plane or spherical or has a specially selected wavefront shape, moreover, the reference wave is plane or spherical, or has a specially selected wavefront shape. 42. The method according to any of paragraphs. 27-41, wherein the inspection wave is applied at an arbitrary angle to the surface of the waveguide. 43. The method according to any of paragraphs. 27-42, wherein the predistorted object wave when recording the diffractive optical element is fed at an arbitrary angle to the waveguide surface, while the angle of incidence of the predistorted object wave on the waveguide surface is equal to the angle of incidence of the inspection wave on the waveguide surface when detecting aberrations. 44. The method according to any one of paragraphs. 27-43, each of said diffractive optical elements being fixed to the waveguide at a predetermined location. 45. The method according to any one of paragraphs. 27-44, wherein the waveguide and fragments of said one or more recorded diffractive media may have defects that cause aberrations when waves propagate through them. 46. The method according to any one of paragraphs. 27-45, wherein the waveguide is flat or curved. 47. A waveguide with diffractive optical elements, made by the method according to any one of paragraphs. 27-46. 48. A waveguide according to claim 47, wherein said diffractive optical elements comprise: one or more input diffractive optical elements for inputting an image into the waveguide, one or more multiplying diffractive optical elements made with the possibility of increasing the geometric dimensions of the transmitted image, and one or more output diffractive optical elements for outputting an image from the waveguide. 49. A virtual and augmented reality device containing a waveguide with diffractive optical elements, according to any one of claims 47-48. 50. The device according to claim 49, configured to input the original image from the image source into the waveguide with diffractive optical elements, increase the geometric dimensions of the image and output a virtual image free from aberrations from the waveguide with diffractive optical elements into the user's eye. 51. A device according to claim 49 or 50, adapted to compensate for aberrations caused by local structures of a waveguide with diffractive optical elements when transmitting an image through a waveguide with diffractive optical elements. 52. Device according to any one of paragraphs. 49-51, and the source of the image is a projector. 53. A method of operation of a virtual and augmented reality device containing a waveguide with diffractive optical elements, according to any one of claims. 49-52, and the method contains: - supply of the original image to the waveguide with diffractive optical elements from the image source, - image transmission through a waveguide with diffractive optical elements with compensation for aberrations caused by local structures of a waveguide with diffractive optical elements, - output of a virtual image, free from aberrations, from a waveguide with diffractive optical elements into the user's eye. 54. The method according to claim 53, comprising increasing the geometric dimensions of the image in the process of image transmission through a waveguide with diffractive optical elements...

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