公开(公告)号：US20240272339A1

公开(公告)日：2024-08-15

申请号：US18167742

申请日：2023-02-10

Applicant: Meta Platforms Technologies, LLC

Inventor： Sawyer MILLER ,  Hsien-Hui CHENG ,  Mengfei WANG ,  Gary D. SHARP ,  Lu LU

IPC: G02B5/18 ,  G02B5/30 ,  G02B5/32 ,  G02B27/28 ,  G03H1/04

CPC classification number: G02B5/1833 ,  G02B5/3016 ,  G02B5/32 ,  G02B27/283 ,  G03H1/0402 ,  G03H2001/0439 ,  G03H2223/13

Abstract: A device includes a Pancharatnam-Berry phase (“PBP”) film stack configured to diffract an input beam as a first polarized beam and a second polarized beam having opposite handednesses. A combined diffraction efficiency of the PBP film stack for the first and second polarized beams is greater than a predetermined value. The device also includes a compensation film stack coupled with the PBP film stack, and configured to respectively convert the first polarized beam and the second polarized beam into a third polarized beam and a fourth polarized beam having the opposite handednesses. The first and second polarized beams include at least one elliptically polarized beam, and the third and fourth polarized beams are two circularly polarized beams. The compensation film stack is configured to convert the at least one elliptically polarized beam into at least one of the two circularly polarized beams.