Active region-less polymer modulator integrated on a common PIC platform and method

Patent metadata

Field	Value
Publication number	US-11262605-B2
Application number	US-201916710066-A
Country	US
Kind code	B2
Filing date	Dec 11, 2019
Priority date	Aug 31, 2017
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A monolithic PIC including a monolithic laser formed in/on a platform and a polymer modulator monolithically built onto the platform and optically coupled to the laser. The modulator includes a first cladding layer, a passive core region with a surface abutting a surface of the first cladding layer, the core region extending to define an input and an output for the modulator. A shaped electro-optic polymer active component has a surface abutting a surface of a central portion of the core region. The active component is polled to align dipoles and promote modulation of light and has a length that extends only within a modulation area defined by modulation electrodes. A second cladding layer encloses the active component and is designed to produce adiabatic transition of light waves traveling in the core region into the active component to travel the length thereof and return to the core region.

First claim

The invention claimed is:

1. A monolithic photonic integrated circuit comprising:
a platform;
a monolithic laser formed in or on the platform; and
a polymer modulator monolithically built onto the platform, the polymer modulator including:
a first cladding layer;
a passive core region with a surface abutting a surface of the first cladding layer, the passive core region extending to define an optical input optically coupled to the monolithic laser and an optical output for the modulator;
a shaped electro-optic polymer active component with a surface abutting a surface of a central portion of the passive core region, the shaped electro-optic polymer active component being polled to align dipoles and promote modulation of light, the shaped electro-optic polymer active component having a length that extends only within a modulation area defined by modulation electrodes, the electro-optic polymer active component has an EO coefficient (r 33 ) greater than 250 pm/v, a glass transition temperature (Tg) 150° C. to 200° C. and a resistivity approximately 10 8 Ohm-cm;
a second cladding layer enclosing the shaped electro-optic polymer active component and designed to produce adiabatic transition of light waves traveling in the passive core region into the shaped electro-optic polymer active component to travel the length of the shaped electro-optic polymer active component and return to the passive core region; and
the first and second cladding layers have levels of conductivity equal to or higher than the electro-optic polymer active component, and the first and second cladding layers have a glass transition temperature (Tg) approximately the same as the Tg of the electro-optic polymer active component, and a resistivity, at room temperature, greater than approximately 10 8 Ohm-cm, and a resistivity much less than the resistivity of the electro-optic polymer active component at poling temperature.

2. The monolithic photonic integrated circuit as claimed in claim 1 wherein the monolithic laser consists of a distributed feedback (DFB) laser, a Fabry-Perot (FB) laser, a distributed Bragg reflector (DBR) laser, a tunable laser, or a VCSEL (Vertical Cavity Surface Emitting Laser).

3. The monolithic photonic integrated circuit as claimed in claim 1 wherein the polymer modulator consists of an intensity modulator, a Mach-Zehnder modulator, a directional-coupler modulator, or a polarization modulator.

4. The monolithic photonic integrated circuit as claimed in claim 3 wherein the polymer modulator includes a Mach-Zehnder interferometer type modulator.

5. The monolithic photonic integrated circuit as claimed in claim 1 wherein the platform is formed of InP.

6. The monolithic photonic integrated circuit as claimed in claim 1 wherein the polymer modulator is optically coupled to the monolithic laser by one of free space, polymer waveguides, or semiconductor material waveguides.

7. The monolithic photonic integrated circuit as claimed in claim 5 wherein the polymer modulator is optically coupled to the monolithic laser by waveguides including InP waveguides.

8. The monolithic photonic integrated circuit as claimed in claim 1 wherein the polymer modulator is optically coupled to the monolithic laser by waveguides consisting of 3-layer, 4-layer or 5-layer polymer waveguides.

9. The monolithic photonic integrated circuit as claimed in claim 1 wherein the polymer modulator is a Mach-Zehnder interferometer modulator optically coupled to the monolithic laser by waveguides consisting of Y-splitters and combiners or multimode interference splitters and combiners.

10. The monolithic photonic integrated circuit as claimed in claim 1 wherein the polymer modulator includes multilayer polymer waveguides having a propagation loss less than 2.2 dB/cm with device insertion loss less than 6 dB.

11. The monolithic photonic integrated circuit as claimed in claim 10 wherein the polymer modulator and multilayer polymer waveguides consist of a ridge waveguide or an inverted ridge waveguide.

12. A monolithic photonic integrated circuit comprising:
a substrate;
a lower electrode on the substrate;
a monolithic laser formed in or on the substrate;
a polymer modulator monolithically built onto the substrate and optically coupled to the monolithic laser by waveguides including polymer waveguides, the polymer modulator including:
a lower cladding layer on the lower electrode;
a passive core region formed on the lower cladding layer and extending to define an optical input and an optical output for the modulator;
a side cladding layer beside the passive core region and forming a planarized surface on the passive core region and lower cladding layer;
a shaped electro-optic polymer active component formed on a central portion of the passive core region of the planarized surface, the shaped electro-optic polymer active component being polled to align dipoles and promote modulation of light, the shaped electro-optic polymer active component having a length that extends only within a modulation area, the electro-optic polymer active component has an EO coefficient (r 33 ) greater than 250 pm/v, a glass transition temperature (Tg) 150° C. to 200° C. and a resistivity approximately 10 8 Ohm-cm;
an upper cladding layer enclosing the shaped electro-optic polymer active component and designed to produce adiabatic transition of light waves in the passive core region into the shaped electro-optic polymer active component to travel the length of the shaped electro-optic polymer active component and return to the passive core region, and the upper and lower cladding layers have a glass transition temperature (Tg) approximately the same as the Tg of the electro-optic polymer active component, and a resistivity, at room temperature, greater than approximately 10 8 Ohm-cm, and a resistivity much less than the resistivity of the electro-optic polymer active component at poling temperature; and
an upper electrode overlying the shaped electro-optic polymer active component so as to define with the lower electrode the modulation area.

13. The monolithic photonic integrated circuit as claimed in claim 12 wherein the monolithic laser consists of a distributed feedback (DFB) laser, a Fabry-Perot (FB) laser, a distributed Bragg reflector (DBR) laser, a tunable laser, or a VCSEL (Vertical Cavity Surface Emitting Laser).

14. The monolithic photonic integrated circuit as claimed in claim 12 wherein the polymer modulator consists of an intensity modulator, a Mach-Zehnder modulator, a directional-coupler modulator, or a polarization modulator.

15. The monolithic photonic integrated circuit as claimed in claim 12 wherein the substrate includes InP.

16. The monolithic photonic integrated circuit as claimed in claim 12 wherein the polymer modulator is optically coupled to the monolithic laser waveguides including InP.

17. The monolithic photonic integrated circuit as claimed in claim 16 wherein the waveguides have a propagation loss less than 2.2 dB/cm with device insertion loss less than 6 dB.

18. The monolithic photonic integrated circuit as claimed in claim 12 wherein the polymer modulator and waveguides consist of a ridge waveguide or an inverted ridge waveguide.

19. The monolithic photonic integrated circuit as claimed in claim 12 wherein the polymer modulator is a Mach-Zehnder interferometer modulator optically coupled to the monolithic laser by waveguides consisting of splitters, combiners, multimode interference splitters or multimode interference combiners.

20.

Assignees

• Lightwave Logic Inc

Inventors

• Lebby Michael
• Enami Yasufumi

Classifications

• G02B6/136

  by etching · CPC title

• G02F1/065 Primary

  in an optical waveguide structure · CPC title

• H01S5/4031

  Edge-emitting structures · CPC title

• H01S5/1032

  Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region · CPC title

• G02F1/212

  Mach-Zehnder type · CPC title