Method and device for performing wavelength modulation with Distributed Bragg Reflector (DBR) laser

• US 7,436,871 B2
• Filed: 12/03/2004
• Issued: 10/14/2008
• Est. Priority Date: 12/03/2004
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Zah, Chung-En, Hu, Martin H
• Primary Examiner(s): Jackson, Jr.; Jerome
• Assistant Examiner(s): SAYADIAN, HRAYR
• Application Number:
  US11/002,978
• Publication Number:
  US 20060120416A1
• Time in Patent Office: 1,411 Days
• Field of Search: 372/26, 372/29.014, 372/29.016, 372/38.01, 372/38.02, 372/38.07, 372/50.011
• US Class Current: 372/50.11
• CPC Class Codes: H01S 5/0092 for nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity
• CPC Class Codes: H01S 5/06253 Pulse modulation
• CPC Class Codes: H01S 5/06256 with DBR-structure
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

The present invention is directed to a method and system for providing phase modulated current to a semiconductor laser to control beam wavelength. A first current is received into a gain portion of the semiconductor laser and a second current is received into a DBR portion of the semiconductor laser. The second current is phase modulated based upon a required intensity value. An output beam is generated by the semiconductor laser based upon the received first current and the received second current.

Claims

1. A method for providing phase modulated current to a semiconductor laser, comprising:

receiving a first current into a gain portion of the semiconductor laser;

phase modulating a second current relative to said first current, based upon required nonzero wavelength modulation, and changing the phase difference between said first current and said second current;

receiving the second current into a DBR portion of the semiconductor laser; and

generating an output beam by the semiconductor laser based upon the received first current and the received second current.

2. The method of claim 1, wherein the first current maintains a constant duty cycle.

3. The method of claim 2, wherein the duty cycle is 50% or less.

4. The method of claim 1, wherein the second current maintains a constant duty cycle.

5. The method of claim 4, wherein the duty cycle is 50% or less.

6. The method of claim 1 further comprising:

converting the output beam generated from the semiconductor laser at a device and having an output intensity modulated due to the wavelength modulation of the semiconductor laser.

7. The method of claim 6, wherein the device is a second harmonic generation device which does change the wavelength of the output beam of the semiconductor laser.

8. The method of claim 6, wherein the device is a passive optical filter device that does not change the wavelength of the output beam of the semiconductor laser.

9. The method of claim 2, wherein a bit period associated with the duty cycle is 5 ns to 150 ns.

10. The method of claim 4, wherein a bit period associated with the duty cycle is 5 ns to 150 ns.

11. A system for providing phase modulated current to a semi-conductor laser to control wavelength modulation of a beam generated by the laser, comprising:

a controller structured to obtain a required intensity value and to convert it to a phase differential value;

current sources structured to inject a first current into a gain portion of the semiconductor laser and a second current into a DBR portion of the semiconductor laser,

a phase modulator operatively connected to said current sources, said phase modulator structured to (i) phase modulate said second current with respect to said first current, and (ii) provide a changing phase differential value Φ

between the first current and the second current,

so that the laser generates an output beam that is wavelength modulated based upon the changing phase differential value Φ

between the first current and the second current.

12. The system of claim 11, wherein the first current maintains a constant duty cycle.

13. The system of claim 12, wherein the duty cycle is 50% or less.

14. The system of claim 11, wherein the second current maintains a constant duty cycle.

15. The system of claim 14, wherein the duty cycle is 50% or less.

16. The system of claim 11 further comprising:

a converter that converts the output beam generated from the semiconductor laser to a beam having an output intensity modulated due to the wavelength modulation of the semiconductor laser.

17. The system of claim 16, wherein the converter is a second harmonic generation device which does change the wavelength of the output beam of the semiconductor laser.

18. The system of claim 16, wherein the converter is a passive optical filter device that does not change the wavelength of the output beam of the semiconductor laser.

19. The system of claim 12, wherein a bit period associated with the duty cycle is 5 ns to 150 ns.

20. The system of claim 14, wherein a bit period associated with the duty cycle is 5 ns to 150 ns.

21. A system for providing phase modulated current to a semiconductor laser to control wavelength modulation of a beam generated by the semiconductor laser, comprising:

a controller means for obtaining a required intensity value and converting it to a non-zero changing phase differential value between a first current and a second current, and for-phase modulating the second current with respect to the first current, based on the phase differential value; and

current source means for injecting (i) the first current into a gain portion of the semiconductor laser and (ii) the second current into a DBR portion of the semiconductor laser, said current means being operatively connected to said controller means,

the laser generating an output beam having a wavelength modulated based upon the phase differential value between the first current and second current.

22. The system of claim 21 further comprising:

converter means for receiving the beam output from the semiconductor laser and for generating a beam having an output intensity modulated due to the wavelength modulation of the semiconductor laser.