Augmented reality device based on waveguide with holographic diffractive grating structure and apparatus for recording the holographic diffractive grating structure

Patent metadata

Field	Value
Publication number	US-11835922-B2
Application number	US-202117411916-A
Country	US
Kind code	B2
Filing date	Aug 25, 2021
Priority date	Aug 25, 2020
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

Provided is an augmented reality (AR) device based on a waveguide with a holographic diffractive grating structure and an apparatus for recording the holographic diffractive grating structure. The apparatus includes a light source, a beam splitter, a first amplitude filter and a first triangular prism that are arranged on a path of a first light beam, and a second amplitude filter and a second triangular prism that are arranged on a path of a second light beam, in which a first part of the first light beam passes through the first triangular prism without attenuation, a second part of the first light beam passes through the first triangular prism after being attenuated, and the second light beam passes through the second triangular prism after being attenuated, and the holographic diffractive grating structure is recorded between the first triangular prism and the second triangular prism.

First claim

What is claimed is:

1. An apparatus for recording a holographic diffractive grating structure, the apparatus comprising:
a light source configured to output light;
a beam splitter configured to split the light output from the light source into a first light beam and a second light beam;
a first amplitude filter and a first triangular prism that are provided on a path of the first light beam; and
a second amplitude filter and a second triangular prism that are provided on a path of the second light beam,
wherein the first amplitude filter is provided such that a first part of the first light beam is directed to the first triangular prism without passing through the first amplitude filter and a second part of the first light beam, which is different from the first part, is directed to the first triangular prism after being attenuated by passing through the first amplitude filter,
wherein the first triangular prism is provided such that the first part of the first light beam is incident on a first surface of the first triangular prism, which corresponds to one of equal sides of an isosceles triangle, and exits through a first exit surface of the first triangular prism, which corresponds to a base of the isosceles triangle, and the second part of the first light beam is incident on a second surface of the first triangular prism, which corresponds to the other side of the equal sides of the isosceles triangle, and exits through the first exit surface,
wherein the second triangular prism is provided such that the second light beam is attenuated by passing through the second amplitude filter, is incident on a first surface of the second triangular prism, and exits through a second exit surface of the second triangular prism, the second exit surface of the second triangular prism being separated from and parallel to the first exit surface of the first triangular prism, and
wherein a diffractive grating material for recording the holographic diffractive grating structure is provided between the first exit surface of the first triangular prism and the second exit surface of the second triangular prism.

2. The apparatus of claim 1 , wherein an incident angle at which the first part of the first light beam is incident on the first surface of the first triangular prism and an incident angle at which the second part of the first light beam is incident on the second surface of the first triangular prism are equal.

3. The apparatus of claim 1 , further comprising at least one of a first light beam expander provided on a path of the first light beam between the beam splitter and the first amplitude filter, the first light expander being configured to expand a beam width of the first light beam and a second light beam expander provided on a path of the second light beam between the beam splitter and the second amplitude filter, the second light beam expander being configured to expand a beam width of the second light beam.

4. The apparatus of claim 1 , further comprising at least one of a first light path conversion member provided on a path of the first light beam between the beam splitter and the first triangular prism, the first light path conversion member being configured to convert the path of the first light beam and a second light conversion member provided on a path of the second light beam between the beam splitter and the second triangular prism, the second light path conversion member being configured to convert the path of the second light beam.

5. The apparatus of claim 1 , wherein the light source comprises a coherent light source.

6. The apparatus of claim 1 , further comprising:
a first shutter provided behind the first amplitude filter; and
a second shutter provided behind the second amplitude filter.

7. The apparatus of claim 1 , further comprising a rotation table that is provided between the first exit surface of the first triangular prism and the second exit surface of the second triangular prism that is parallel to the first exit surface of the first triangular prism, the rotation table comprising a top surface on which the diffractive grating material for recording the holographic diffractive grating structure is provided.

8. A method of recording a holographic grating structure by an apparatus configured to record the holographic diffractive grating structure of claim 1 , the method comprising:
generating light by a light source;
splitting the light into a first light beam and a second light beam by a beam splitter;
directing a first part of the first light beam to a first surface of a first triangular prism, which corresponds to one of equal sides of an isosceles triangle, without passing through the first amplitude filter;
attenuating a second part of the first light beam, which is different from the first part, by the first amplitude filter, and directing the second part to a second surface of the first triangular prism, which corresponds to the other of the equal sides of the isosceles triangle;
directing the first part of the first light beam and the second part of the first light beam to be incident on the first surface and the second surface of the first triangular prism, refracting the first part and the second part, and directing the first part and the second part to exit from a first exit surface of the first triangular prism, which corresponds to a base of the isosceles triangle;
attenuating the second light beam by the second amplitude filter, directing the second light beam to be incident on a first surface of the second triangular prism, refracting the second light beam, and directing the second light beam to exit through a second exit surface of the second triangular prism;
providing a diffractive grating material for recording the holographic diffractive grating structure between the first exit surface of the first triangular prism and the second exit surface of the second triangular prism;
forming an interference pattern by the first part of the first light beam and the second part of the first light beam based on the first part of the first light beam and the second part of the first light beam being incident on the diffractive grating material through the first exit surface of the first triangular prism and recording a first diffractive grating in the diffractive grating material; and
forming an interference pattern by the first part of the first light beam and the second light beam based on the second light beam being incident on the diffractive grating material through the second exit surface of the second triangular prism and recording a second diffractive grating in the diffractive grating material.

9. The method of claim 8 , wherein an incident angle at which the first part of the first light beam is incident on the first surface of the first triangular prism and an incident angle at which the second part of the first light beam is incident on the second surface of the first triangular prism are equal, such that a maximum intensity and a minimum intensity of the interference pattern by the first part of the first light beam and the second part of the first light beam are formed vertically in a depth direction on a first surface of the diffractive grating material.

10. The method of claim 9 , wherein the maximum intensity and the minimum intensity of the interference pattern by the first part of the first light beam and the second part of the first light beam are formed at an angle to a second surface of the diffractive grating material, which opposes the first surface of the diffractive grating material.

11. The method of claim 8 , wherein the first refractive grating comprises an expanded diffractive grating, and the second refractive grating comprises an o

Assignees

• Samsung Electronics Co Ltd

Inventors

• Muravev Nikolay Victorovich
• Borisov Vladimir Nikolaevich
• Popov Mikhail Vyacheslavovich

Classifications

• G03H1/0402 Primary

  Recording geometries or arrangements (G03H1/0443, G03H1/0476, G03H1/16 take precedence) · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title

• G02B2027/0174

  holographic · CPC title

• G03H2001/0441

  Formation of interference pattern, not otherwise provided for · CPC title

• G03H2223/18

  Prism · CPC title