US 11,940,653 B2
Diffractive optical waveguide and display device having the same
Zhentao Fan, Tongxiang (CN); Xingming Zhao, Tongxiang (CN); and Kehan Tian, Tongxiang (CN)
Assigned to JIAXING UPHOTON OPTOELECTRONICS TECHNOLOGY CO., LTD., Tongxiang (CN)
Filed by JIAXING UPHOTON OPTOELECTRONICS TECHNOLOGY CO., LTD., Tongxiang (CN)
Filed on May 11, 2023, as Appl. No. 18/315,738.
Claims priority of application No. 202210522596.6 (CN), filed on May 13, 2022.
Prior Publication US 2023/0367078 A1, Nov. 16, 2023
Int. Cl. G02B 6/34 (2006.01); F21V 8/00 (2006.01); G02B 27/01 (2006.01); G02B 27/09 (2006.01)
CPC G02B 6/34 (2013.01) [G02B 6/0036 (2013.01); G02B 27/0172 (2013.01); G02B 27/0955 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A diffraction optical waveguide, comprising a waveguide substrate and a grating structure formed on the waveguide substrate, wherein,
the grating structure comprises a plurality of optical unit structures arranged in an array along a plane, wherein each optical unit structure is a concave hole structure or a convex structure formed on the waveguide substrate and has a first end and a second end in a first direction parallel to the plane, and a distance between the first end and the second end along the first direction is a length L of each optical unit structure;
each optical unit structure has a maximum width W perpendicular to the first direction in a predetermined section along the first direction, where 0.3L≤W≤0.7L;
in the first direction, a central position of the predetermined section is at a predetermined distance d from the first end, where d<0.5L, and a width of each optical unit structure in a direction perpendicular to the first direction gradually decreases from the predetermined section to the first end as well as from the predetermined section to the second end, so that a centroid of a cross-section of each optical unit structure parallel to the plane is closer to the first end relative to the second end;
the grating structure is configured as a coupling-out grating, the coupling-out grating couples at least a part of the light propagating thereinto along a coupling-in direction within the waveguide substrate, out of the waveguide substrate by diffraction, and the coupling-in direction is substantially parallel to the first direction; and
the first end of each optical unit structure is located upstream along the coupling-in direction, and the second end is located downstream along the coupling-in direction.