US 12,292,627 B2
Optical device
Hiroshi Take, Hong Kong (CN); Kenji Nagase, Hong Kong (CN); Anthony Reymund Melad Binarao, Hong Kong (CN); Cheng Bu Heng, Hong Kong (CN); and Atsushi Shimura, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Mar. 29, 2022, as Appl. No. 17/707,675.
Claims priority of application No. 202110340343.2 (CN), filed on Mar. 30, 2021; and application No. 202210296419.0 (CN), filed on Mar. 24, 2022.
Prior Publication US 2022/0326555 A1, Oct. 13, 2022
Int. Cl. G02F 1/225 (2006.01); G02B 6/12 (2006.01); G02B 6/122 (2006.01); G02F 1/03 (2006.01); G02F 1/035 (2006.01); G02F 1/21 (2006.01)
CPC G02F 1/035 (2013.01) [G02B 6/122 (2013.01); G02F 1/0305 (2013.01); G02F 1/212 (2021.01); G02F 1/225 (2013.01); G02B 2006/12097 (2013.01); G02F 2202/20 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An optical device comprising:
a substrate;
an optical waveguide formed on the substrate; and
a protrusion portion formed adjacent to the optical waveguide on the substrate, wherein in a cross section perpendicular to a propagation direction of light:
the protrusion portion includes a first side that faces the optical waveguide and a second side that faces away from the optical waveguide with a top end of the first side and a top end of the second side intersecting at a peak,
the first side slopes downward from the peak toward the optical waveguide and the second side slopes downward from the peak away from the optical waveguide, and
an incline of a slope of the second side with respect to an upper surface of the substrate is smaller than an incline of a slope of the first side with respect to the upper surface of the substrate,
wherein the peak of the protrusion portion is separated from a side surface of the optical waveguide by a distance of 40% to 60% of a height of the optical waveguide,
wherein a height of the peak of the protrusion portion is 5% to 35% of the height of the optical waveguide, and
wherein a ratio of the height of the peak of the protrusion portion to the distance that the peak of the protrusion portion is separated from the side surface of the optical waveguide is between 0.08 and 0.70.