Method and System For Modulation Of Gain Suppression In High Average Power Laser Systems

Abstract

A high average power laser system with modulated gain suppression includes an input aperture associated with a first laser beam extraction path and an output aperture associated with the first laser beam extraction path. The system also includes a pinhole creation laser having an optical output directed along a pinhole creation path and an absorbing material positioned along both the first laser beam extraction path and the pinhole creation path. The system further includes a mechanism operable to translate the absorbing material in a direction crossing the first laser beam extraction laser path and a controller operable to modulate the second laser beam.

1 . A method of operating a first laser, the method comprising:
 providing the first laser having an optical cavity;   disposing an absorbing material in the optical cavity;   providing a second laser;   directing a beam from the second laser to impinge on the absorbing material;   vaporizing a portion of the absorbing material;   forming a pinhole in the optical cavity; and   outputting a laser pulse from the first laser.   
     
     
         2 . The method of  claim 1  wherein the first laser comprises a Nd:SrF2 laser. 
     
     
         3 . The method of  claim 1  wherein the second laser comprises a YAG laser. 
     
     
         4 . The method of  claim 1  wherein the absorbing material comprise at least one of comprises at least one of graphite, carbon fiber, plastic, aluminum, steel, or tungsten. 
     
     
         5 . The method of  claim 1  wherein the pinhole is characterized by a spatial dimension ranging from about 0.1 mm to about 1.0 mm. 
     
     
         6 . The method of  claim 1  wherein the laser pulse is characterized by a power greater than 10 KW. 
     
     
         7 . A method of providing modulated gain suppression for a high average power laser system, the method comprising:
 providing a first laser beam path associated with a first pulsed laser system;   providing a first portion of an absorbing material disposed in the first laser beam path;   pulsing the first pulsed laser system to generate a first pulse propagating along the first laser beam path;   vaporizing the first portion of the absorbing material to generate a plasma shutter at a pinhole location along the first laser beam path;   dissipating the plasma shutter;   forming at pinhole at the pinhole location;   passing at least a portion of the first pulse through the pinhole location; and   translating the absorbing material to position a second portion of the absorbing material at the pinhole location.   
     
     
         8 . The method of  claim 7  wherein vaporizing the first portion of the absorbing material comprises:
 providing a second laser beam path associated with a second pulsed laser system, wherein the second laser beam path intersects the first laser beam path at the pinhole location; 
 pulsing the second pulsed laser system to generate a second pulse propagating along the second laser beam path. 
 
     
     
         9 . The method of  claim 7  wherein the first pulsed laser system comprises a Nd:SrF2 laser. 
     
     
         10 . The method of  claim 9  wherein the at least a portion of the first pulse is characterized by an average power ranging from 200 KW to 2 MW. 
     
     
         11 . The method of  claim 7  wherein the absorbing material comprises at least one of graphite, carbon fiber, plastic, aluminum, steel, or tungsten. 
     
     
         12 . The method of  claim 7  wherein translating the absorbing material comprises operation of a reel-to-reel system using a ribbon of the absorbing material. 
     
     
         13 . The method of  claim 7  the second portion of the absorbing material is positioned at the pinhole location within 10 ms of the formation of the pinhole.