Optical waveguide element and optical modulator using the same

Patent metadata

Field	Value
Publication number	US-2019079366-A1
Application number	US-201816185337-A
Country	US
Kind code	A1
Filing date	Nov 9, 2018
Priority date	Aug 21, 2015
Publication date	Mar 14, 2019
Grant date	—

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:
an input side; an output side; and an optical waveguide located between the input side and the output side, wherein light applied from the input side propagates through the optical waveguide and emerges at the output side, wherein the optical waveguide includes:
a slab part in which a maximum thickness of lithium niobate film is a first thickness; and
a ridge part in which a maximum thickness of lithium niobate film is a second thickness greater than the first thickness,
wherein the first thickness is 0.05 times or more and less than 0.4 times a wavelength of the light, 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 0.5 times or more and less than 2.0 times the wavelength of the light.

2 . An optical modulator comprising:
an optical waveguide element; 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 optical waveguide element comprising:
an input side;
an output side; and
an optical waveguide located between the input side and the output side, wherein light applied from the input side propagates through the optical waveguide and emerges at the output side,
wherein the optical waveguide includes:
a slab part in which a maximum thickness of lithium niobate film is a first thickness; and
a ridge part in which a maximum thickness of lithium niobate film is a second thickness greater than the first thickness,
wherein the first thickness is 0.05 times or more and less than 0.4 times a wavelength of the light, 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 0.5 times or more and less than 2.0 times the wavelength of the light.

3 . An optical waveguide element comprising:
an input side; an output side; and an optical waveguide located between the input side and the output side, wherein light applied from the input side propagates through the optical waveguide and emerges at the output side, wherein the optical waveguide includes:
a slab part in which a maximum thickness of lithium niobate film is a first thickness; and
a ridge part in which a maximum thickness of lithium niobate film is a second thickness greater than the first thickness,
wherein the first thickness is 0.05×1.55 μm or more and less than 0.4×1.55 μm, wherein a width of the ridge part is 0.1×1.55 μm or more and less than 1.0×1.55 μm, and wherein a thickness of the ridge part is 0.5×1.55 μm or more and less than 2.0×1.55 μm.

Assignees

• Tdk Corp

Inventors

• Iwatsuka Shinji
• Sasaki Kenji
• Shirai Satoshi

Classifications

• G02F1/2257 Primary

  the optical waveguides being made of semiconducting material · CPC title

• G02F2001/212

  Physics · mapped topic

• G02B6/122

  Basic optical elements, e.g. light-guiding paths · CPC title

• G02F2202/20

  LiNbO3, LiTaO3 · CPC title

• G02B6/126

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