Phase shifter employing transparent electrodes

Patent metadata

Field	Value
Publication number	US-12197100-B2
Application number	US-202117189025-A
Country	US
Kind code	B2
Filing date	Mar 1, 2021
Priority date	Mar 3, 2020
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

Electro-optical devices and methods for constructing electro-optical devices such as a switch or phase shifter. An electrode layer is deposited on a substrate layer, a waveguide structure is deposited on the electrode layer, a first cladding layer is deposited on the waveguide structure, and the first cladding layer is planarized and bonded to a wafer. The substrate layer is removed and the electrode layer is etched to split the electrode layer into a first electrode separated from a second electrode. A second cladding layer is deposited on the etched electrode layer. The first and second electrodes may be composed of a material with a large dielectric constant, or they may be composed of a material with a large electron mobility. The device may exhibit a sandwich waveguide architecture where an electro-optic layer is disposed between two strip waveguides.

First claim

What is claimed is:

1. A device, comprising:
a first cladding layer;
a first electrode;
a first metallic lead electrically connected to the first electrode;
a second electrode;
a second metallic lead electrically connected to the second electrode;
a second cladding layer,
a waveguide structure comprising a slab layer, a first strip waveguide portion, and a second strip waveguide portion, wherein the slab layer is disposed between the first strip waveguide portion and the second strip waveguide portion, wherein the first and second strip waveguide portions are composed of silicon nitride, wherein the slab layer is composed of barium titanate, wherein the waveguide structure is coupled to the first electrode and the second electrode, wherein the waveguide structure is disposed between the first and second cladding layers; and
wherein the first electrode and the second electrode are composed of a first material with an electron mobility higher than silicon.

2. A device, comprising:
a first cladding layer;
a first electrode;
a second electrode;
a waveguide structure wherein the waveguide structure comprises a slab layer, a first strip waveguide portion, and a second strip waveguide portion, wherein the slab layer is disposed between the first strip waveguide portion and the second strip waveguide portion, wherein the first and second strip waveguide portions are composed of silicon nitride, wherein the slab layer is composed of a first material, wherein the waveguide structure is coupled to the first electrode and the second electrode; and
a second cladding layer,
wherein the first electrode and the second electrode are composed of a second material with an electron mobility higher than silicon.

3. The device of claim 2 ,
wherein the second material comprises one of:
gallium arsenide (GaAs);
an aluminum gallium arsenide/GaAs heterostructure;
an indium gallium arsenide (InGaAs)/GaAs heterostructure;
zinc oxide (ZnO);
zinc sulfide (ZnS);
indium oxide (InO);
doped silicon;
a two-dimensional electron gas; or
doped strontium titanate.

4. The device of claim 3 ,
wherein the doped strontium titanate is either:
niobium doped;
lanthanum doped; or
vacancy doped.

5. The device of claim 2 ,
wherein the first material comprises one of:
barium titanate;
barium strontium titanate;
lead zirconium titanate;
lead lanthanum zirconium titanate; or
strontium barium niobate.

6. The device of claim 2 ,
wherein the first cladding layer and the second cladding layer are composed of silicon dioxide.

7. The device of claim 2 ,
wherein the first cladding layer is disposed on a first side of the first electrode, second electrode, and waveguide structure, and
wherein the second cladding layer is disposed on a second side of the first electrode, second electrode, and waveguide structure opposite the first side.

8. The device of claim 2 ,
wherein the first electrode and the second electrode are configured to generate an electric field along an x-direction in the waveguide structure, and
wherein the waveguide structure is characterized by an electro-optic coefficient having a nonzero value aligned along the x-direction.

9. The device of claim 2 ,
wherein the first electrode and the second electrode comprise a second layer coplanar to the first strip waveguide portion and disposed adjacent to a first side of the slab layer.

10. The device of claim 2 ,
wherein the first electrode and the second electrode are separated by a gap region.

11. The device of claim 2 , wherein the first material comprises a transparent material having an index of refraction that is larger than an index of refraction of the first and second cladding layers.

12. An optical switch, comprising:
at least one input port;
at least one output port;
a Mach-Zehnder interferometer coupled to a beam splitter, wherein the Mach-Zehnder interferometer comprises a first arm and a second arm;
a photonic phase shifter comprised within the first arm of the Mach-Zehnder interferometer, the photonic phase shifter comprising:
a first cladding layer;
a first electrode;
a second electrode;
a waveguide structure wherein the waveguide structure comprises a slab layer, a first strip waveguide portion, and a second strip waveguide portion, wherein the slab layer is disposed between the first strip waveguide portion and the second strip waveguide portion, wherein the first and second strip waveguide portions are composed of silicon nitride, wherein the slab layer is composed of a first material, wherein the waveguide structure is coupled to the first electrode and the second electrode; and
a second cladding layer,

wherein the first electrode and the second electrode are composed of a second material with an electron mobility higher than silicon.

13. The optical switch of claim 12 ,
wherein the second material comprises one of:
gallium arsenide (GaAs);
an aluminum gallium arsenide/GaAs heterostructure;
an indium gallium arsenide (InGaAs)/GaAs heterostructure;
zinc oxide (ZnO);
zinc sulfide (ZnS);
indium oxide (InO);
doped silicon;
a two-dimensional electron gas; or
doped strontium titanate.

14. The optical switch of claim 12 ,
wherein the first material comprises one of:
barium titanate;
barium strontium titanate;
lead zirconium titanate;
lead lanthanum zirconium titanate; or
strontium barium niobate.

15. The optical switch of claim 12 ,
wherein the first cladding layer and the second cladding layer are composed of silicon dioxide.

16. The optical switch of claim 12 ,
wherein the first cladding layer is disposed on a first side of the first electrode, second electrode, and waveguide structure, and
wherein the second cladding layer is disposed on a second side of the first electrode, second electrode, and waveguide structure opposite the first side.

17. The optical switch of claim 12 ,
wherein the first electrode and the second electrode are configured to generate an electric field along an x-direction in the waveguide structure, and
wherein the waveguide structure is characterized by an electro-optic coefficient having a nonzero value aligned along the x-direction.

18. The optical switch of claim 12 ,
wherein the first electrode and the second electrode comprise a second layer coplanar to the first strip waveguide portion and disposed adjacent to a first side of the slab layer.

19. The optical switch of claim 12 ,
wherein the first electrode and the second electrode are separated by a gap region.

20. The optical switch of claim 12 , wherein the first material comprises a transparent material having an index of refraction that is larger than an index of refraction of the first and second cladding layers.

Assignees

• Psiquantum Corp

Inventors

• Kumar Nikhil

Classifications

• G02F2203/50

  Phase-only modulation · CPC title

• G02F2202/42

  Materials having a particular dielectric constant · CPC title

• G02F2201/12

  electrode · CPC title

• G02F2201/063

  ridge; rib; strip loaded · CPC title

• G02F1/212

  Mach-Zehnder type · CPC title