Optical waveguide device

Patent metadata

Field	Value
Publication number	US-11624965-B2
Application number	US-202117350627-A
Country	US
Kind code	B2
Filing date	Jun 17, 2021
Priority date	Aug 13, 2020
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

An optical waveguide device includes an intermediate layer, a thin-film LN layer including X-cut lithium niobate, and a buffer layer stacked on a substrate; an optical waveguide formed in the thin-film LN layer; and an electrode for driving. The intermediate layer is formed by an upper first intermediate layer and a lower second intermediate layer, the second intermediate layer having a permittivity that is smaller than a permittivity of the first intermediate layer.

First claim

What is claimed is:

1. An optical waveguide device comprising:
an intermediate layer, a thin-film LN layer including X-cut lithium niobate, and a buffer layer covering the thin-film LN layer, wherein the intermediate layer, the thin-film LN layer, and the buffer layer are stacked on a substrate;
a ridge-type optical waveguide formed in the thin-film LN layer; and
an electrode for driving, wherein
the intermediate layer is formed by an upper first intermediate layer and a lower second intermediate layer that is in direct contact with the upper first intermediate layer,
the second intermediate layer having a permittivity that is smaller than a permittivity of the first intermediate layer.

2. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a material containing a metal element of any of group 3 to group 18 of a periodic table.

3. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a material containing an oxide of indium and silicon oxide.

4. The optical waveguide device according to claim 3 , wherein the first intermediate layer further includes a material containing an oxide of another metal or semiconductor element.

5. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a material containing an oxide of titanium and silicon oxide.

6. The optical waveguide device according to claim 5 , wherein the first intermediate layer further includes a material containing an oxide of another metal or semiconductor element.

7. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a material containing an oxide of tin and silicon oxide.

8. The optical waveguide device according to claim 7 , wherein the first intermediate layer further includes a material containing an oxide of another metal or semiconductor element.

9. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a material containing an oxide of germanium and silicon oxide.

10. The optical waveguide device according to claim 9 , wherein the first intermediate layer further includes a material containing an oxide of another metal or semiconductor element.

11. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a material containing an oxide of zinc and silicon oxide.

12. The optical waveguide device according to claim 11 , wherein the first intermediate layer further includes a material containing an oxide of another metal or semiconductor element.

13. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a mixture or compound of silicon oxide and an oxide of at least one species of a metal element of any of group 3 to group 18 of a periodic table.

14. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a mixture or compound of silicon oxide and an oxide of at least one species of a semiconductor element excluding silicon.

15. The optical waveguide device according to claim 1 , wherein the first intermediate layer includes a mixture or compound of silicon oxide and an oxide including at least one species of a semiconductor element excluding silicon and at least one species of a metal element of any of group 3 to group 18 of a periodic table.

16. The optical waveguide device according to claim 1 , wherein a bottom of the electrode is provided at a position lower than is a position of a surface of the buffer layer.

17. The optical waveguide device according to claim 1 , wherein a bottom of the electrode is provided on a step of a predetermined depth position in the buffer layer.

18. The optical waveguide device according to claim 1 , wherein a bottom of the electrode is provided on a step of the thin-film LN layer.

19. The optical waveguide device according to claim 1 , wherein a bottom of the electrode is provided on a step of the first intermediate layer.

20. The optical waveguide device according to claim 1 , wherein a bottom of the electrode is provided on a step of the second intermediate layer.

Assignees

• Fujitsu Optical Components Ltd

Inventors

• Makino Shuntaro
• Kubota Yoshinobu
• Ohmori Yasuhiro
• Doi Masaharu
• Kurahashi Teruo

Classifications

• G02B2006/1204

  Lithium niobate (LiNbO3) · CPC title

• G02B6/12 Primary

  of the integrated circuit kind (electric integrated circuits H10B, H10D84/00 - H10D89/00, H10F19/00, H10F39/00, H10H29/00, H10K19/00, H10K39/00, H10K59/00, H10N19/00, H10N39/00, H10N59/00, H10N69/00, H10N79/00, H10N89/00) · CPC title

• G02F1/212

  Mach-Zehnder type · CPC title

• G02F1/0316

  Electrodes · CPC title

• G02F1/2257 Primary

  the optical waveguides being made of semiconducting material · CPC title