Use of volume bragg gratings for the conditioning of laser emission characteristics
Apparatus and methods for altering one or more spectral, spatial, or temporal characteristics of a light-emitting device are disclosed. Generally, such apparatus may include a volume Bragg grating (VBG) element that receives input light generated by a light-emitting device, conditions one or more characteristics of the input light, and causes the light-emitting device to generate light having the one or more characteristics of the conditioned light.
1 . Apparatus for conditioning a characteristic of an array of laser emitters, the apparatus comprising:
an array of laser emitters;
a wavelength multiplexer that multiplexes respective light emitted by each of the emitters into a single output channel of multiplexed light; and
a retro-reflecting device that reflects at least a portion of the multiplexed light back into the multiplexer such that each emitter in the array receives respective wavelength-selective feedback from the multiplexer.
2 . Apparatus according to claim 1 , wherein the wavelength-selective feedback causes each of the emitters to operate at a respective wavelength associated with a multiplexer channel to which the emitter is optically coupled.
3 . Apparatus according to claim 2 , wherein the respective light emitted by each of the emitters goes through the respective multiplexer channel to which the emitter is optically coupled.
4 . Apparatus according to claim 2 , wherein the wavelength multiplexer is adapted to combine the light going through the multiplexer channels into the single output channel of multiplexed light.
5 . Apparatus according to claim 1 , wherein the wavelength multiplexer comprises one or more Bragg grating elements.
6 . Apparatus according to claim 1 , wherein the wavelength multiplexer comprises a monolithic glass element having a plurality of wavelength-specific Bragg gratings recorded therein.
7 . Apparatus according to claim 1 , wherein respective light emitted by each of the emitters goes through a respective wavelength channel in the wavelength multiplexer to which the emitter is coupled, and wherein the wavelength multiplexer combines the respective wavelength channels into the single output channel of multiplexed light.
8 . Apparatus according to claim 1 , wherein the retro-reflecting device reflects the portion of the multiplexed light such that the reflected portion retraces a path back through the multiplexer and into the array of emitters, such that each emitter in the array receives respective wavelength-selective feedback from the multiplexer that causes each of the emitters to operate at the wavelength of a respective multiplexer channel to which the emitter is coupled.
9 . Apparatus according to claim 1 , wherein the wavelength multiplexer is positioned in an optical path of light emitted by the array.