公开(公告)号：WO2020176528A1

公开(公告)日：2020-09-03

申请号：PCT/US2020/019727

申请日：2020-02-25

Applicant: FACEBOOK TECHNOLOGIES, LLC.

Inventor： VORA, Ankit ,  MOHANTY, Nihar Ranjan ,  LANE, Austin ,  COLBURN, Matthew E. ,  FRANKE, Elliott

IPC: G02B5/18 ,  G03F7/004 ,  H01J37/305

Abstract: Disclosed herein are techniques for fabricating straight or slanted variable-etch-depth gratings. A photoresist material for fabricating a variable-etch-depth grating in a substrate is sensitive to light with a wavelength shorter than 300 nm and has an etch rate comparable to the etch rate of the substrate. A depth of an exposed portion of a photoresist material layer including the photoresist material correlates with the exposure dose. After exposure using a gray-scale mask and development, the photoresist material layer has a non-uniform thickness. The photoresist material layer with the non-uniform thickness and the underlying substrate are etched using a straight etching or slanted etching process to form the straight or slanted variable-etch-depth grating in the substrate. The variable-etch-depth grating is characterized by a non-uniform depth profile corresponding to the non-uniform thickness of the photoresist material layer before etching.

公开(公告)号：WO2022060485A1

公开(公告)日：2022-03-24

申请号：PCT/US2021/045043

申请日：2021-08-06

Applicant: FACEBOOK TECHNOLOGIES, LLC

Inventor： FRANKE, Elliott ,  MOHANTY, Nihar Ranjan ,  LANE, Austin ,  COLBURN, Matthew E. ,  VORA, Ankit

IPC: G02B5/18 ,  G02B27/01

Abstract: A method of fabricating gratings with variable grating depths including depositing a first grating material layer with a uniform thickness profile on a substrate, forming an etch mask layer having a variable thickness profile on the first grating material layer, etching the etch mask layer and the first grating material layer to change the uniform thickness profile of the first grating material layer to a non-uniform thickness profile, forming a patterned hard mask on the first grating material layer, and etching, using the patterned hard mask, the first grating material layer to form a grating with a variable depth in the first grating material layer.

公开(公告)号：WO2020242785A1

公开(公告)日：2020-12-03

申请号：PCT/US2020/033070

申请日：2020-05-15

Applicant: FACEBOOK TECHNOLOGIES, LLC

Inventor： VORA, Ankit

IPC: G02B27/00 ,  G02B6/34 ,  G02B27/01 ,  G02B27/42

Abstract: An imaging waveguide for a visual display includes a substrate for guiding image light therein by total internal reflection (TIR). An input grating is supported by the substrate for coupling the image light into the imaging waveguide. An output grating is supported by the substrate and spaced apart from the input grating for coupling the image light guided in the substrate out of the imaging waveguide for observation by a user. A gap filling overcoat is formed on and within the output grating, but not on or within the input grating. The material is characterized by a refractive index between 1.40 and 1.80 at 500 nm, absorption between 0% and 1% in the visible region of the electromagnetic spectrum, and % haze between 0% and 0.2% in the visible region of the electromagnetic spectrum.

公开(公告)号：WO2020163334A1

公开(公告)日：2020-08-13

申请号：PCT/US2020/016584

申请日：2020-02-04

Applicant: FACEBOOK TECHNOLOGIES, LLC

Inventor： PERLMUTTER, Zachary ,  VORA, Ankit ,  LANE, Austin ,  CALAFIORE, Giuseppe ,  COLBURN, Matthew, E. ,  RAO, Tingling

IPC: G03F7/00

Abstract: Disclosed herein is a nanoimprint lithography (NIL) precursor material comprising a base resin component having a first refractive index ranging from 1.45 to 1.80, and a nanoparticles component having a second refractive index greater than the first refractive index of the base resin component. According to certain embodiments, further disclosed herein are a cured NIL material made by curing the NIL precursor material, a NIL grating comprising the cured NIL material, an optical component comprising the NIL grating, and methods for forming the NIL grating and the optical component using a NIL process.