US 12,345,918 B2
Slab waveguide layer for enhanced near-eye-display surface relief grating lightguide
Kevin Messer, Mountain View, CA (US); David Alexander Sell, Santa Clara, CA (US); and Samarth Bhargava, Saratoga, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jun. 21, 2024, as Appl. No. 18/750,069.
Application 18/750,069 is a continuation of application No. 18/496,574, filed on Oct. 27, 2023, granted, now 12,050,344.
Claims priority of provisional application 63/381,323, filed on Oct. 28, 2022.
Prior Publication US 2024/0337789 A1, Oct. 10, 2024
Int. Cl. G02B 6/122 (2006.01); G02B 6/12 (2006.01)
CPC G02B 6/1223 (2013.01) [G02B 6/12007 (2013.01); G02B 2006/12107 (2013.01); G02B 2207/101 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A waveguide, comprising:
a waveguide substrate, having a substrate refractive index (RI) nsub;
a slab waveguide layer disposed over the waveguide substrate, the slab waveguide layer having a slab RI nswg;
an incoupler grating defined by a first portion of a plurality of grating structures in the slab waveguide layer, the grating structures of the incoupler grating are disposed in the slab waveguide layer such that the incoupler grating has a depth from a lower surface to an upper surface of the slab waveguide layer between the grating structures of the incoupler grating;
a fold grating defined by a second portion of the plurality of grating structures and an outcoupler grating defined by a third portion of the plurality of grating structures in the slab waveguide layer, the second portion is separated from the third portion, the slab waveguide layer has a slab depth dswg from the lower surface to the upper surface of the slab waveguide layer between the grating structures of the fold grating and the outcoupler grating, the slab depth dswg is greater than the depth of the incoupler grating; and
a superstrate between and over the grating structures, the superstrate having a superstrate RI nsuperstrate and an interface with the slab waveguide layer, wherein the slab RI nswg is greater than the substrate RI nsub and the slab RI nswg is greater than the superstrate RI nsuperstrate.