公开(公告)号：US20240411069A1

公开(公告)日：2024-12-12

申请号：US18670486

申请日：2024-05-21

Applicant: Snap Inc.

Inventor： Akheelesh Kumar Abeeluck ,  Alexander Drayton ,  Marcell Kiss ,  Parashara Panduranga

IPC: G02B5/18

Abstract: A stepped diffraction grating and method for manufacturer thereof are disclosed. A plurality of parallel grating lines are each formed on a substrate surface by forming a plurality of stacked layers of optically transmissive material. In cross-section, each grating line has an upper layer having an upper surface having a first end and a second end; a bottom layer having a bottom surface abutting the substrate surface and an upper surface having a first end and a second end; a rising staircase portion extending at a rising staircase angle between 10 degrees and 60 degrees; and a falling staircase portion extending at a falling staircase angle between the rising staircase angle and 89 degrees.