External cavity laser with a tunable holographic element

Abstract

Embodiments of systems and methods are provided for a tunable laser device. The tunable laser device may include a tunable Bragg reflector that allows its wavelength to be tuned via temperature and/or pressure. This Bragg reflector may include holographic material in which a Bragg grating may be formed comprising parallel fringes of alternating index of refractions. Temperature and/or pressure changes may be effected in the Bragg reflector by, for example, a thermoelectric cooler and/or piezo transducer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates an exemplary laser system, in accordance with embodiments of methods and systems of the present invention;

FIG. 2 illustrates an exemplary tunable Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 3 illustrates an alternative exemplary embodiment of a tunable Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 4 illustrates yet another alternative exemplary embodiment of a tunable Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 5 illustrates normalized efficiency curves for an exemplary Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 6 provides an exemplary flow chart of a method for designing a tunable Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 7 illustrates a simplified diagram of an optical system for fabricating a tunable Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 8 illustrates a simplified emission of a laser which utilizes an exemplary tunable Bragg reflector, in accordance with embodiments of methods and systems of the present invention;

FIG. 9 illustrates an alternative exemplary laser system, in accordance with embodiments of methods and systems of the present invention; and

FIG. 10 illustrates an alternative exemplary laser system, in accordance with embodiments of methods and systems of the present invention.

Claims

1. A system for generating a coherent light beam, comprising: a coherent light source;a lens which collimates the light to provide a collimated coherent light beam; anda reflective device which is tunable to reflect at least a portion of a tuned wavelength of light of the collimated coherent light beam, wherein the reflective device is responsive to at least one of temperature and/or pressure to adjust the tuned wavelength.

2. The system of claim 1, wherein the reflective device comprises a material comprising a Bragg grating.

3. The system of claim 2, wherein the Bragg grating is formed by parallel fringes and wherein the fringes comprise alternating indexes of refraction.

4. The system of claim 3, wherein the parallel fringes are formed by directing a plane wave coherent beam through the material which is reflected such that the plane wave passes back through the material to create a standing wave that forms the Bragg grating.

5. The system of claim 1, further comprising a thermoelectric device which can effect a temperature change in the reflective device to adjust the wavelength of light to which the reflective device is tuned.

6. The system of claim 1, further comprising a transducer which can effect a pressure change in the reflective device to adjust the wavelength of light to which the reflective device is tuned.

7. The system of claim 1, wherein the system comprises an optical cavity having an optical cavity length and wherein the optical cavity length can be adjusted.

8. The system of claim 7, further comprising a mount connected to the reflective device, wherein the optical cavity length can be adjusted by effecting at least one of a temperature, pressure, or mechanical change in the mount connected to the reflective device.

9. A method for generating a coherent light beam, comprising the following steps: (a) providing a collimated coherent light beam; and(b) adjusting at least one of a temperature of the reflective device and/or a pressure applied to the reflective device to tune the reflective device such that the reflective device reflects at least a portion of a tuned wavelength of light of the collimated coherent light beam.

10. The method of claim 9, wherein the reflective device comprises a material comprising a Bragg grating.

11. The method of claim 10, further comprising forming the Bragg grating by effecting parallel fringes in the material, wherein the fringes comprise alternating indexes of refraction.

12. The method of claim 11, wherein forming the parallel fringes in the material comprises: directing a plane wave through the material; andreflecting the plane wave after passing through the material such that the plane wave is reflected back through the material.

13. The method of claim 9, further comprising adjusting a temperature of the reflective device to adjust the wavelength of light to which the reflective device is tuned.

14. The method of claim 9, further comprising adjusting a pressure applied to the reflective device to adjust the wavelength of light to which the reflective device is tuned.

15. The method of claim 9, wherein the system comprises an optical cavity having an optical cavity length, and wherein the method further comprises adjusting the optical cavity length.

16. The method of claim 15, wherein adjusting the optical cavity length comprises effecting at least one of a temperature, pressure, or mechanical change in a mount connected to the reflective device.

17. A system for generating a coherent light beam, comprising: means for providing a collimated coherent light beam;means for tuning a reflective device;means for adjusting at least one of temperature of the tuning means and/or a pressure applied to the tuning means such that the tuning means reflects at least a portion of a tuned wavelength of light of the collimated coherent light beam.

18. The system of claim 17, wherein the tuning means comprises a material comprising a Bragg grating having parallel fringes in the material, wherein the fringes comprise alternating indexes of refraction.

19. The system of claim 17, further comprising means for adjusting a temperature of the tuning means to adjust the wavelength of light to which the tuning means is tuned.

20. The system of claim 17, further comprising means for adjusting a pressure applied to the tuning means to adjust the wavelength of light to which the tuning means is tuned.

21. The system of claim 17, wherein the system comprises an optical cavity having an optical cavity length, and wherein the system further comprises means for adjusting the optical cavity length.

22. The system of claim 21, wherein the optical cavity length adjusting means comprises means for effecting at least one of a temperature, pressure, or mechanical change in a mount connected to the reflective device.