Diffractive optical elements (DOEs) for high tolerance of structured light

Patent metadata

Field	Value
Publication number	US-10895752-B1
Application number	US-201815867463-A
Country	US
Kind code	B1
Filing date	Jan 10, 2018
Priority date	Jan 10, 2018
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

Disclosed herein are techniques for structured light pattern generation. A method for generating a one-dimensional structured light pattern in a first direction and with a desired intensity pattern includes generating a plurality of one-dimensional light patterns using a two-dimensional diffractive optical element with different periods in two orthogonal directions, and combining the plurality of one-dimensional light patterns to form the one-dimensional structured light pattern with the desired intensity pattern. Each of the one-dimensional light patterns includes a one-dimensional light pattern in the first direction. The plurality of one-dimensional light patterns is distributed in a second direction different from the first direction. A separation angle between each pair of adjacent one-dimensional light patterns of the plurality of one-dimensional light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than a threshold value.

First claim

What is claimed is:

1. A method for generating a one-dimensional structured light pattern in a first direction and with a desired intensity pattern, the method comprising:
generating, using a two-dimensional diffractive optical element with different periods in two orthogonal directions, a plurality of one-dimensional diffracted light patterns, wherein:
each of the one-dimensional diffracted light patterns includes a one-dimensional diffracted light pattern in the first direction;
the plurality of one-dimensional diffracted light patterns are distributed in a second direction different from the first direction; and
each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns at least partially overlaps in the second direction at a target plane; and

combining the plurality of one-dimensional diffracted light patterns to form the one-dimensional structured light pattern with the desired intensity pattern.

2. The method of claim 1 , wherein:
a separation angle between each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than a threshold value.

3. The method of claim 2 , wherein:
the separation angle between each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than 0.5 degree.

4. The method of claim 2 , wherein:
the separation angle between each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than 0.2 degree.

5. The method of claim 1 , wherein:
a period of the two-dimensional diffractive optical element in the second direction is at least 40 times of a period of the two-dimensional diffractive optical element in the first direction.

6. The method of claim 1 , wherein:
a period of the two-dimensional diffractive optical element in the second direction is at least 100 times of a period of the two-dimensional diffractive optical element in the first direction.

7. The method of claim 1 , wherein:
the one-dimensional structured light pattern with the desired intensity pattern is a monochromatic light pattern.

8. The method of claim 1 , wherein:
an angle of view of the one-dimensional structured light pattern is greater than 100° in the first direction; and
an angle of view of the one-dimensional structured light pattern is less than 5° in the second direction.

9. The method of claim 1 , wherein:
the desired intensity pattern is a non-uniform pattern.

10. The method of claim 1 , wherein combining the plurality of one-dimensional diffracted light patterns to form the one-dimensional structured light pattern with the desired intensity pattern includes:
combining the plurality of one-dimensional diffracted light patterns using an optical element configured to concentrate light in a direction perpendicular to each of the plurality of one-dimensional diffracted light patterns.

11. An optical device for generating a one-dimensional structured light pattern in a first direction and with a desired intensity pattern, the optical device comprising:
a two-dimensional diffractive optical element configured to generate a plurality of one-dimensional diffracted light patterns, wherein:
each of the one-dimensional diffracted light patterns includes a one-dimensional light pattern in the first direction;
the plurality of one-dimensional diffracted light patterns are distributed in a second direction different from the first direction; and
each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns at least partially overlaps in the second direction at a target plane.

12. The optical device of claim 11 , wherein:
a separation angle between each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than a threshold value.

13. The optical device of claim 12 , wherein:
the separation angle between each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than 0.5 degree.

14. The optical device of claim 12 , wherein:
the separation angle between each pair of adjacent one-dimensional diffracted light patterns of the plurality of one-dimensional diffracted light patterns in the second direction and with respect to the two-dimensional diffractive optical element is less than 0.2 degree.

15. The optical device of claim 11 , wherein:
a period of the two-dimensional diffractive optical element in the second direction is at least 40 times of a period of the two-dimensional diffractive optical element in the first direction.

16. The optical device of claim 11 , wherein:
a period of the two-dimensional diffractive optical element in the second direction is at least 100 times of a period of the two-dimensional diffractive optical element in the first direction.

17. The optical device of claim 11 , wherein:
the two-dimensional diffractive optical element has a multilevel or continuous phase profile in each period.

18. The optical device of claim 11 , further comprising:
an optical element configured to concentrate light in a direction perpendicular to each of the plurality of one-dimensional diffracted light patterns.

19. An optical device for generating a one-dimensional structured light pattern in a first direction and with a desired intensity pattern, the optical device comprising: a two-dimensional diffractive optical element, wherein a period of the two-dimensional diffractive optical element in a second direction is configured such that each pair of adjacent diffraction spots at least partially overlap in the second direction at a target plane, and wherein a period of the two-dimensional diffractive optical element in the first direction is smaller than the period of the two-dimensional diffractive optical element in the second direction.

20. The optical device of claim 19 , wherein:
a separation angle of diffraction spots in the second direction with respect to the optical device is less than 0.5 degree.

21. The optical device of claim 19 , wherein:
a separation angle of the diffraction spots in the second direction with respect to the optical device is less than 0.2 degree.

22. The optical device of claim 19 , wherein:
the period of the two-dimensional diffractive optical element in the second direction is at least 100 times of the period of the two-dimensional diffractive optical element in the first direction.

Assignees

• Facebook Tech Llc

Inventors

• Romano Nitay
• Grossinger Nadav
• Layosh Yaakov Yonatan

Classifications

• G01B11/2513

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title

• G02B5/1866

  Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence) · CPC title

• G02B5/1842 Primary

  Gratings for image generation (G02B5/1847 takes precedence) · CPC title

• G06F3/011

  Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00) · CPC title

• G02B27/425 Primary

  in illumination systems (mask illumination systems in photolithographic systems G03F7/70158) · CPC title