Optical waveguide element and optical modulator using the same

Patent metadata

Field	Value
Publication number	US-10203583-B2
Application number	US-201815906280-A
Country	US
Kind code	B2
Filing date	Feb 27, 2018
Priority date	Aug 21, 2015
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

Disclosed herein is an optical waveguide element that includes a substrate and a waveguide layer formed on the substrate and comprising lithium niobate. The waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part. The maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part.

First claim

What is claimed is:

1. An optical waveguide element comprising:
a substrate; and
a waveguide layer formed on the substrate and comprising lithium niobate,
wherein the waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part,
wherein a maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part,
wherein a width of the ridge part is 0.1 times or more and less than 1.0 time the wavelength of the light, and
wherein a thickness of the ridge part is 0.6 times or more and less than 1.5 times the wavelength of the light.

2. The optical waveguide element as claimed in claim 1 , wherein the maximum thickness of the slab part is 0.2 times or more the wavelength of the light.

3. The optical waveguide element as claimed in claim 1 , wherein sides of the ridge part are inclined by 70° or more.

4. An optical modulator comprising:
an optical waveguide element including:
a substrate; and
a waveguide layer formed on the substrate and comprising lithium niobate; and

a multimode interference branching waveguide in which a propagation loss is larger in a m=1 mode than in a m=0 mode, the multimode interference branching waveguide being connected to the optical waveguide element,
wherein the waveguide layer has a slab part having a predetermined thickness and a ridge part protruding from the slab part, and
wherein a maximum thickness of the slab part is 0.05 times or more and less than 0.4 times a wavelength of a light propagating in the ridge part.

5. The optical modulator as claimed in claim 4 , wherein the maximum thickness of the slab part is 0.2 times or more the wavelength of the light.

6. The optical modulator as claimed in claim 4 , wherein a thickness of the ridge part is 0.6 times or more and less than 1.5 times the wavelength of the light.

Assignees

• Tdk Corp

Inventors

• Iwatsuka Shinji
• Sasaki Kenji
• Shirai Satoshi

Classifications

• G02F2202/20

  LiNbO3, LiTaO3 · CPC title

• G02F1/2257 Primary

  the optical waveguides being made of semiconducting material · CPC title

• G02F2001/212

  Physics · mapped topic

• G02B6/126

  using polarisation effects {(G02B6/1226 takes precedence)} · CPC title

• G02F2203/07

  Polarisation dependent · CPC title