Tunable semiconductor laser system

• US 20010017876A1
• Filed: 01/16/2001
• Published: 08/30/2001
• Est. Priority Date: 06/04/1999
• Status: Active Grant

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: Bandwidth9, Inc.
• Inventors: Li, Gabriel, Yuen, Wupen, Worland, D. Phillip, Kner, Peter, Yu, Rang-Chen
• Granted Patent: US 6,351,476 B2
• Time in Patent Office: Days
• US Class Current: 372/50
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01S 5/0078 for frequency filtering
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/06804 by monitoring an external parameter, e.g. temperature
• CPC Class Codes: H01S 5/0687 Stabilising the frequency of the laser
• CPC Class Codes: H01S 5/18366 Membrane DBR, i.e. a movable DBR on top of the VCSEL

Abstract

A tunable semiconductor laser system includes a laser with a semiconductor active region positioned between upper and lower confining regions of opposite type semiconductor material. First and second reflective members are positioned at opposing edges of the active and confining regions. A wavelength tuning member and a temperature sensor are coupled to the laser. A control loop is coupled to the temperature sensor and the tuning member. In response to a detected change in temperature the control loop sends an adjustment signal to the tuning member and the tuning member adjusts a voltage or current supplied to the laser to provide a controlled output beam of selected wavelength.

Claims

1. A tunable semiconductor laser system, comprising:

an edge emitter or VCSEL laser including a semiconductor active region positioned between upper and lower confining regions of opposite type semiconductor material, and first and second reflective members positioned at opposing edges of the active and confining regions, the laser producing an output beam;

a wavelength tuning member monolithically formed with the laser;

a frequency sensor coupled to the laser; and

a control loop coupled to the frequency sensor and the tuning member, wherein in response to a detected change in frequency the control loop sends an adjustment signal to the tuning member and the tuning member adjusts a voltage or current supplied to the laser to provide a controlled frequency and power of an output beam.

2. The laser system of

claim 1

, wherein the control loop provides a laser output beam wavelength stability that is less than a spacing of a channel of a WDM.

3. The laser system of

claim 1

, wherein the control loop provides a laser output beam wavelength tuning range of 1530 and 1625 nm.

4. The laser system of

claim 1

, wherein the control loop provides a laser output beam wavelength stability of at least 0.2 nm.

5. The laser of

claim 1

, further comprising:

a substrate with a substrate seal ring, the laser being positioned on a surface of the substrate; and

a seal cap including a seal ring, wherein the seal cap seal ring is coupled to the substrate seal ring and form a hermetic seal of the laser in an area defined by the seal cap and the substrate.

6. The laser system of

claim 1

, wherein the frequency sensor and the laser are positioned on the substrate.

7. The laser system of

claim 1

, wherein the frequency sensor and the laser form an integral assembly.

8. The laser system of

claim 1

, wherein the frequency sensor and the laser form a monolithically integrated chip.

9. The laser system of

claim 1

, wherein the control loop provides wavelength stability over a temperature range of −

20°

-85°

C.

10. The laser system of

claim 1

, wherein the control loop provides wavelength stability over a temperature range of 0°

-70°

C.

11. The laser system of

claim 1

, wherein the control loop provides the adjustment signal to the tuning member in response to a difference in a measured frequency and a desired frequency of the laser.

12. A tunable semiconductor laser system, comprising:

a laser including,

an electrically responsive substrate;

a support block positioned on the electrically responsive substrate;

a top reflecting member and a bottom reflecting member;

a first cantilever structure including a base section resting on the support block, a deformable section extending above the electrically responsive substrate and creating an air gap between the deformable section and the electrically responsive substrate, and an active head positioned at a predetermined location on the deformable section and including at least a portion of the top reflecting member;

a frequency sensor that forms an integral assembly with the laser; and

a control loop coupled to the frequency sensor and the first cantilever structure, wherein in response to a detected change in frequency the control loop adjusts an electric charge applied to the substrate to provide a controlled frequency and power of an output beam.

13. The laser system of

claim 12

, wherein the control loop provides a laser output beam wavelength stability that is less than a spacing of a channel of a WDM.

14. The laser system of

claim 12

, wherein the control loop provides a laser output beam wavelength tuning range of 1530 and 1625 nm.

15. The laser system of

claim 12

, wherein the control loop provides a laser output beam wavelength stability of at least 0.2 nm.

16. The laser of

claim 12

, further comprising:

a substrate with a substrate seal ring, the laser being positioned on a surface of the substrate; and

a seal cap including a seal ring, wherein the seal cap seal ring is coupled to the substrate seal ring and form a hermetic seal of the laser in an area defined by the seal cap and the substrate.

17. The laser system of

claim 12

, wherein the frequency sensor and the laser are positioned on the substrate.

18. The laser system of

claim 12

, wherein the frequency sensor and the laser form a monolithically integrated chip.

19. The laser system of

claim 12

, wherein the control loop provides wavelength stability over a temperature range of −

20°

-85°

C.

20. The laser system of

claim 12

, wherein the control loop provides wavelength stability over a temperature range of 0°

-70°

C.

21. The laser system of

claim 12

, wherein the control loop provides the adjustment signal to the tuning member in response to a difference in a measured frequency and a desired frequency of the laser.

22. A tunable semiconductor laser system, comprising:

an edge emitter or VCSEL laser including a semiconductor active region positioned between upper and lower confining regions of opposite type semiconductor material, and first and second reflective members positioned at opposing edges of the active and confining regions, the laser producing an output beam;

a frequency tuning mechanism;

a wavelength selective filter including a Fabry-Perot Etalon that provides positional dependence of a wavelength reflection or transmission of the wavelength selective filter and transmit or reflect the beam to at least first and second photodetectors;

a fixed frequency reference filter;

a control loop coupled to the frequency tuning mechanism, wavelength selective filter and the fixed frequency reference filter, the control loop adjusting a frequency of the output beam to a predetermined frequency is response.

23. The system of claim 100, wherein the control loop compares voltage of a reference output from the fixed frequency reference filter to a voltage of the Fabry-Perot Etalon to adjust