US 12,393,090 B2
Optical device
Kenji Nagase, Hong Kong (CN); Hiroshi Take, Hong Kong (CN); Anthony Reymund Melad Binarao, Hong Kong (CN); and Cheng Bu Heng, Hong Kong (CN)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Mar. 27, 2023, as Appl. No. 18/190,252.
Claims priority of application No. 202210330416.4 (CN), filed on Mar. 31, 2022.
Prior Publication US 2023/0314852 A1, Oct. 5, 2023
Int. Cl. G02F 1/21 (2006.01); G02F 1/03 (2006.01); G02F 1/035 (2006.01); G02F 1/225 (2006.01)
CPC G02F 1/212 (2021.01) [G02F 1/03 (2013.01); G02F 1/0316 (2013.01); G02F 1/035 (2013.01); G02F 1/225 (2013.01); G02F 2201/07 (2013.01); G02F 2202/20 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An optical device comprising:
a substrate;
an optical waveguide provided in a predetermined region of the substrate and formed of an electro-optic material film;
a protective layer formed adjacent to the optical waveguide; and
a non-light-propagation optical waveguide provided outside the predetermined region, wherein,
a surface roughness of the non-light-propagation optical waveguide is RMS 0.5 nm or more, and
the non-light-propagation optical waveguide is a waveguide that is not configured to transmit an optical signal,
wherein a surface roughness on a side of the non-light-propagation optical waveguide is formed in a striped pattern,
wherein the side of the non-light-propagation optical waveguide is a side facing the optical waveguide and is transverse to the substrate, and
wherein a plurality of stripes forming the striped pattern are formed in an elongated shape extending in a direction which intersects the substrate.