ON-CHIP INTEGRATED GAS SENSOR BASED ON PHOTONIC SENSING

• US 20150323450A1
• Filed: 05/07/2015
• Published: 11/12/2015
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: Cornell University
• Original Assignee: Cornell University
• Inventors: Lipson, Michal, Gaeta, Alexander, Fain, Romy, Griffith, Austin G., Cardenas, Jaime, Lau, Ryan K.W., Okawachi, Yoshitomo
• Granted Patent: US 10,088,414 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 2201/0612 Laser diodes
• CPC Class Codes: G01N 2201/0635 Structured illumination, e.g. with grating
• CPC Class Codes: H01L 31/0232 Optical elements or arrangements associated with the device H01L31/0236 takes precedence; for photovoltaic cells H01L31/054; for photovoltaic modules H02S40/20
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 31/105 the potential barrier being of the PIN type

Abstract

Techniques, systems, and devices are disclosed to provide on-chip integrated gas sensor based on photonic sensing. For example, a sensing device is provided to include an optical comb generator that produces an optical comb of different optical comb frequencies in a mid-infrared (MIR) spectral range to interact with a sample under detection, the optical comb generator including a substrate, an optical resonator formed on the substrate and an optical waveguide formed on the substrate and coupled to the optical resonator, and an optical detector that detects light from the sample at the different optical comb frequencies.

Claims

1. A photonic device, comprising:

an optical comb generator that produces an optical comb of different optical comb frequencies in a mid-infrared (MIR) spectral range to interact with a sample under detection, the optical comb generator including an integrated circuit that includes a silicon substrate, an optical resonator formed on the silicon substrate via an etchless process by thermal oxidation without etching to achieve a high quality factor in the optical resonator, an PIN junction embedded in the optical resonator, metal contacts formed on the PIN junction and an optical waveguide formed on the substrate and coupled to the optical resonator; and

an optical detector that detects light from the sample at the different optical comb frequencies.

2. The device as in claim 1, wherein the optical detector is formed on the substrate.

3. The device as in claim 1, wherein the optical detector is formed outside the substrate.

4. The device as in claim 1, wherein the optical comb generator is a CMOS compatible device.

5. The device as in claim 1, wherein the optical waveguide includes a silicon material.

6. The device as in claim 1, wherein the PIN junction includes a p-doped region on one side of the optical resonator and an n-doped region on an opposing side of the optical resonator.

7. The device as in claim 1, wherein the optical resonator has a ring shape.

8. The device as in claim 1, wherein the substrate includes a silicon-on-insulator structure and the optical resonator is formed of a silicon part and is embedded in the PIN junction.

9. The device as in claim 1, wherein light is coupled into the optical resonator via the waveguide, the light coming from an on chip source or off chip source.

10. The device as in claim 1, wherein the optical detector is provided for contaminate detection, air quality monitors, biological specimen testing, or testing for microbes with MIR absorbing dyes.

14. A method of operating the photonic device as in claim 1, comprising:

providing a reverse bias to the PIN junction to extract carriers generated therein; and

directing pump light at a pump frequency into the optical resonator to cause nonlinear optical interactions to generate optical comb frequencies.

15. The method of claim 14, wherein the optical comb frequencies are in a mid-infrared (MIR) spectral range to interact with a sample under detection.

16. The method of claim 14, further comprising:

directing the optical comb frequencies into a gas sample to obtain optical measurements of the gas sample.

11. A method of fabricating an optical comb generator, comprising:

providing a silicon-on-insulator structure;

forming an optical waveguide resonator by performing a thermal oxidation of a silicon part on the silicon-on-insulator structure without etching the silicon to achieve a high quality factor;

doping portions of the silicon to provide a PIN junction, the optical waveguide resonator being embedded in the PIN junction; and

forming metal contacts for the PIN junction.

12. The method of claim 11, the providing of the optical waveguide includes:

depositing silicon nitride over the silicon-on-insulator structure; and

patterning the silicon nitride to form a silicon nitride mask.

13. The method of claim 11, further comprising:

forming the metal contacts by using metal vias.