US 11,841,523 B2
Diffractive optical waveguide and display device
Yuming Song, Beijing (CN); and Kehan Tian, Beijing (CN)
Assigned to JIAXING UPHOTON OPTOELECTRONICS TECHNOLOGY CO., LTD., Jiaxing (CN)
Filed by JIAXING UPHOTON OPTOELECTRONICS TECHNOLOGY CO., LTD., Zhejiang (CN)
Filed on Apr. 11, 2023, as Appl. No. 18/132,982.
Claims priority of application No. 202210399540.6 (CN), filed on Apr. 15, 2022.
Prior Publication US 2023/0333301 A1, Oct. 19, 2023
Int. Cl. F21V 8/00 (2006.01); G02B 27/01 (2006.01); G02B 27/00 (2006.01); G02B 6/34 (2006.01)
CPC G02B 6/0016 (2013.01) [G02B 27/0081 (2013.01); G02B 27/0172 (2013.01); G02B 6/34 (2013.01); G02B 2027/0178 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A diffractive optical waveguide for optical pupil expansion, comprising:
a waveguide substrate;
a coupling-in grating disposed on or in the waveguide substrate and configured to couple input light into the waveguide substrate to cause light to propagate within the waveguide substrate through total reflection;
a coupling-out grating disposed on or in the waveguide substrate and configured to couple out at least a portion of light propagating therein from the waveguide substrate by diffraction, wherein,
the coupling-out grating comprises a first coupling-out grating, a second coupling-out grating and a third coupling-out grating, all of which are arranged successively in a first direction; the second coupling-out grating is disposed between the first coupling-out grating and the third coupling-out grating, and comprises a two-dimensional grating; the second coupling-out grating is corresponding to a region that includes a first edge and a second edge spaced in a second direction orthogonal to the first direction, wherein the first edge is closer to the coupling-in grating than the second edge, and a first width of the first edge in the first direction is greater than a second width of the second edge in the first direction; light output by the coupling-in grating is incident on the second coupling-out grating through the waveguide substrate, and is diffracted by the second coupling-out grating into a plurality of beam splits, the plurality of beam splits include a first beam split propagating within the region of the second coupling-out grating, a second beam split propagating toward the first coupling-out grating or the third coupling-out grating, and a third beam split propagating in the same direction as the propagation direction of light output by the coupling-in grating, and the third beam split is propagable to the first coupling-out grating or the third coupling-out grating.