公开(公告)号：US12222530B2

公开(公告)日：2025-02-11

申请号：US17557917

申请日：2021-12-21

Applicant: TOPPAN INC.

Inventor： Masashi Kawashita ,  Yukari Oda

IPC: G02B5/26 ,  H01L27/146

Abstract: An optical device including a concavo-convex structure layer composed of a plurality of protrusions arranged having a subwavelength period; a high refractive index layer located on the concavo-convex structure and having a surface shape following the concavo-convex structure; and a low refractive index layer located on the high refractive index layer and having a surface shape following a concavo-convex structure on a surface of the high refractive index layer. The high refractive index layer includes a first grating high refractive index region located on a bottom of the concavo-convex structure to form a subwavelength grating, and a second grating high refractive index region located on a top of the concavo-convex structure to form a subwavelength grating. The high refractive index layer has a refractive index higher than both the refractive indices of the concavo-convex structure layer and the low refractive index layer.