Temperature sensor integrated with MOS capacitor for stabilizing lasers

Patent metadata

Field	Value
Publication number	US-10897119-B1
Application number	US-201916570830-A
Country	US
Kind code	B1
Filing date	Sep 13, 2019
Priority date	Sep 13, 2019
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

Techniques and circuitry for a semiconductor laser with enhanced lasing wavelengths stabilization are described. A semiconductor laser can generate an optical signal (e.g., single or multi-wavelength), for use in a Dense Wavelength Division Multiplexing (DWDM) interconnect system. The stabilization circuitry can include temperature sensor circuitry that measures an operational temperature of the semiconductor laser, and a feedback controller that can determine a temperature-induced wavelength shift that may be experienced by the multi-wavelength optical signal based on the laser's temperature. The feedback controller is also configured to generate a compensation signal that is determined to cause a complimentary shift in the multi-wavelength optical signal, where the complimentary shift can compensate for the temperature-induced wavelength shift. An integrated MOS capacitor of the laser can be charged by the signal in a manner that effectuates the complimentary shift and tunes the multi-wavelength optical signal to compensate for temperature-induced shift, thereby enhancing stabilization.

First claim

What is claimed is:

1. A circuit for stabilizing lasing wavelengths of a laser, comprising:
laser circuitry generating a optical signal having at least one wavelength;
temperature sensor circuitry measuring a signal indicative of an operational temperature of the laser circuitry;
a metal-oxide semiconductor (MOS) capacitor integrated within the laser circuitry; and
controller circuitry receiving the signal from the temperature sensor circuitry such that an operation temperature of the laser circuitry is determined and generating a control signal for tuning the MOS capacitor to compensate for a wavelength shift of the optical signal based on the determined operation temperature of the laser circuitry.

2. The circuit of claim 1 , wherein the MOS capacitor is formed within the laser circuitry by deposited a capacitor dielectric between a III-V material and silicon.

3. The circuit of claim 2 , wherein the MOS capacitor receives the control signal generated by the controller circuitry and tunes the laser circuitry to generate a shifted optical signal such that the wavelength shift of the multi-optical signal is compensated.

4. The circuit of claim 3 , wherein the temperature sensor circuitry comprises a resistor proximal to the laser circuitry.

5. The circuit of claim 4 , wherein the signal indicative of the operational temperature of the laser circuitry comprises a voltage across the resistor.

6. The circuit of claim 5 , wherein the temperature sensor circuit comprises a diode.

7. The circuit of claim 6 , wherein the diode is integrated proximal to the laser circuitry.

8. The circuit of claim 6 , wherein the diode is integrated within the laser circuitry.

9. The circuit of claim 6 , wherein the signal indicative of the operational temperature of the laser circuitry comprises a voltage signal across the diode.

10. The circuit of claim 6 , wherein the temperature sensor circuit comprises:
a light source;
a Mach-Zehnder Interferometer (MZI) receiving light from the light source further transmitting the light; and
a photodetector measuring power associated with the transmitted light from the MZI.

11. The circuitry of claim 10 , wherein the signal indicative of the operational temperature of the laser circuitry comprises the power measured by the photodetector.

12. The circuitry of claim 3 , wherein the controller determines a value of temperature-induced wavelength shift based on the measured temperature.

13. The circuitry of claim 12 , wherein the control signal generated by the control circuitry comprises a voltage corresponding to the value of temperature-induced wavelength, and the voltage is applied to the MOS capacitor to effectuate a shift that decreases the wavelengths of the optical signal or that increases the wavelengths of the optical signal.

14. A multi-wavelength semiconductor laser with stabilization enhancements, comprising:
a silicon-on-insulator (SOI) substrate layer;
an upper silicon layer deposited on the SOI substrate layer;
a III-V material layer deposited on the upper silicon layer forming an active region of a semiconductor laser to generate a multi-wavelength optical signal;
a dielectric layer deposited between the III-V material layer and the upper silicon layer forming a MOS capacitor, wherein the MOS capacitor tunes the multi-wavelength optical signal for stabilization; and
a temperature sensor layer deposited on the silicon substrate layer, wherein the temperature sensor measures a temperature that is indicative of a temperature-induced wavelength shift of the generated multi-wavelength optical signal.

15. The multi-wavelength semiconductor laser of claim 14 , wherein the MOS capacitor tunes the multi-wavelength optical signal by effectuating a wavelength shift such that compensates for the indicated temperature-induced wavelength shift of the generated multi-wavelength optical signal.

16. The multi-wavelength semiconductor laser of claim 15 , comprising:
a cladding layer; and
a metal layer deposited on the cladding layer receiving an applied voltage that charges the active region of the semiconductor laser to generate a multi-wavelength optical signal.

17. The multi-wavelength semiconductor laser of claim 16 , comprising:
an additional metal layer deposited on the MOS capacitor receiving an additional applied voltage that charges the MOS capacitor to tune the multi-wavelength optical signal.

18. The multi-wavelength semiconductor laser of claim 14 , wherein the temperature sensor layer comprises a silicon diode.

19. A method of stabilization lasing wavelengths of a semiconductor laser, comprising:
measuring a signal indicative of an operational temperature of the semiconductor laser during operation;
determining an operational temperature of the semiconductor laser during operation based on the measured signal;
determining a temperature-induced wavelength shift based on the measured operational temperature; and
generating a compensation signal to apply to an integrated MOS capacitor of the semiconductor laser to compensate for the temperature-induced wavelength shift of the multi-wavelength optical signal.

20. The method of claim 19 , wherein the compensation signal comprises a voltage that is applied to the MOS capacitor to effectuate a shift that decreases the wavelengths of the optical signal or that increases the wavelengths of the optical signal.

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Kurczveil Geza
• Liang Di
• Huang Zhihong
• Zeng Xiaoge
• Beausoleil Raymond G

Classifications

• G01J5/0879

  Optical elements not provided otherwise, e.g. optical manifolds, holograms, cubic beamsplitters, non-dispersive prisms or particular coatings · CPC title

• G01J5/00 Primary

  Radiation pyrometry, e.g. infrared or optical thermometry · CPC title

• H01S5/0687 Primary

  Stabilising the frequency of the laser · CPC title

• H01S5/0208

  Semi-insulating substrates · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title