Method and system for mutliline mir-ir laser

Abstract

A method of performing spatial separation of different wavelengths in a single laser cavity includes generating, from a pump radiation source, pump radiations in spatially separate channels and focusing the generated pump radiations in the spatially separate channels towards an active gain medium having amplification spectra. The method also includes emitting from the active gain medium, amplified radiations of the spatially separate channels, each channel of the spatially separate channels representing a corresponding wavelength and focusing the emitted amplified radiations of the spatially separated channels towards an aperture. The method further includes suppressing, at the aperture, an off-axis mode of the amplified radiations of the spatially separate channels, diffracting the amplified radiations of the spatially separate channels received through the aperture to provide diffracted radiations and returning a portion of the diffracted radiations back to the aperture, and collimating the diffracted radiations of the spatially separate channel.

What is claimed is: 
     
         1 . A method of performing spatial separation of different wavelengths in a single laser cavity, the method comprising:
 generating, from a pump radiation source, pump radiations in spatially separate channels;   focusing the generated pump radiations in the spatially separate channels towards an active gain medium having amplification spectra;   emitting from the active gain medium, amplified radiations of the spatially separate channels, each channel of the spatially separate channels representing a corresponding wavelength;   focusing the emitted amplified radiations of the spatially separated channels towards an aperture;   suppressing, at the aperture, an off-axis mode of the amplified radiations of the spatially separate channels;   diffracting, at a diffraction grating, the amplified radiations of the spatially separate channels received through the aperture to provide diffracted radiations and returning a portion of the diffracted radiations back to the aperture; and   collimating the diffracted radiations of the spatially separate channel.   
     
     
         2 . The method of  claim 1  wherein the active gain medium comprises at least one of a chromium doped ZnS crystal or a chromium doped ZnSe crystal. 
     
     
         3 . The method of  claim 2  wherein the chromium doping varies across a width of the chromium doped ZnS crystal or the chromium doped ZnSe crystal. 
     
     
         4 . The method of  claim 1  further comprising:
 receiving, at the aperture, the portion of the diffracted radiations returned from the diffraction grating; and 
 extracting radiation of main radiation modes from the diffracted radiations. 
 
     
     
         5 . The method of  claim 1  further comprising selecting, at the aperture, fundamental transverse modes of the amplified radiations of the spatially separate channels. 
     
     
         6 . The method of  claim 1  wherein the pump radiation source comprises an array of diode stripes or a fiber bunch. 
     
     
         7 . The method of  claim 1  wherein the diffraction grating comprises a Littrow mount grating. 
     
     
         8 . The method of  claim 1  wherein the active gain medium comprises a high reflectivity (HR) coating and an anti-reflection (AR) coating. 
     
     
         9 . The method of  claim 8  wherein the HR coating comprises a dichroic mirror. 
     
     
         10 . A multiline laser comprising:
 a pump radiation source operable to provide a plurality pump radiations in spatially separate channels;   a pump focusing system optically coupled to the pump radiation source;   a resonant cavity defined by a high reflectivity (HR) mirror and a diffraction grating;   an active gain medium optically coupled to the pump focusing system;   an intracavity lens disposed in the resonant cavity between the active gain medium and the diffraction grating;   an aperture disposed in the resonant cavity between the intracavity lens and the diffraction grating; and   a collimating lens optically coupled to the diffraction grating.   
     
     
         11 . The multiline laser of  claim 10  wherein:
 the active gain medium is operable to produce a plurality of amplified radiations, each of the plurality of amplified radiations characterized by fundamental transverse modes and one or more off-axis modes; and 
 the aperture is operable to select the fundamental transverse modes and suppress the one or more off-axis modes. 
 
     
     
         12 . The multiline laser of  claim 10  wherein the active gain medium comprises at least one of a chromium doped ZnS crystal or a chromium doped ZnSe crystal. 
     
     
         13 . The multiline laser of  claim 12  wherein the chromium doping varies across a width of the chromium doped ZnS crystal or the chromium doped ZnSe crystal. 
     
     
         14 . The multiline laser of  claim 10  wherein the pump radiation source comprises an array of diode stripes or a fiber bunch. 
     
     
         15 . The multiline laser of  claim 10  wherein the diffraction grating comprises a Littrow mount grating. 
     
     
         16 . The multiline laser of  claim 10  wherein the active gain medium comprises a high reflectivity (HR) coating and an anti-reflection (AR) coating. 
     
     
         17 . The multiline laser of  claim 16  wherein the HR coating comprises a dichroic mirror.