Optical waveguide element and optical modulator using the same

Patent metadata

Field	Value
Publication number	US-10585328-B2
Application number	US-201916410926-A
Country	US
Kind code	B2
Filing date	May 13, 2019
Priority date	Aug 21, 2015
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

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 0.05×1.55 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 0.6×1.55 μm or more and less than 1.5×1.55 μm.

2. The optical waveguide element as claimed in claim 1 , wherein the maximum thickness of the slab part is 0.2×1.55 μm or more and less than 0.4×1.55 μm.

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 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, the slab part having inclining parts located at both sides of the ridge part, the inclining parts being gradually thinned away from the ridge part, and
wherein a maximum thickness of the slab part is 0.05×1.55 μm or more and less than 0.4×1.55 μm.

5. The optical waveguide element as claimed in claim 4 , wherein a width of the ridge part is 0.1×1.55 μm or more and less than 1.0×1.55 μm.

6. The optical waveguide element as claimed in claim 4 , wherein a thickness of the ridge part is 0.5×1.55 μm or more and less than 2.0×1.55 μm.

7. The optical waveguide element as claimed in claim 4 , wherein sides of the ridge part are inclined by 70° or more.

8. The optical waveguide element as claimed in claim 4 , wherein a maximum thickness of the inclining parts is 0.1×1.55 μm or more and less than 0.37×1.55 μm.

9. The optical waveguide element as claimed in claim 4 , wherein a width of the ridge part is 0.3×1.55 μm or more and less than 1.2×1.55 μm.

10. 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 0.05×1.55 μm or more and less than 0.4×1.55 μm.

11. The optical modulator as claimed in claim 10 , wherein the maximum thickness of the slab part is 0.2×1.55 μm or more.

12. The optical modulator as claimed in claim 10 , wherein a thickness of the ridge part is 0.6×1.55 μm or more and less than 1.5×1.55 μm.

Assignees

• Tdk Corp

Inventors

• Iwatsuka Shinji
• Sasaki Kenji
• Shirai Satoshi

Classifications

• G02F2203/07

  Polarisation dependent · CPC title

• G02B6/29352

  in a light guide · CPC title

• G02B6/122

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

• G02B6/2813

  based on multimode interference effect, i.e. self-imaging · CPC title

• G02F1/2257 Primary

  the optical waveguides being made of semiconducting material · CPC title