External cavity laser with a tunable holographic element
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.
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; and
a 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; and
reflecting 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.