Thermal management system for high energy laser

Abstract

A method and system are disclosed for cooling a laser, such as a high average power (HAP) solid state laser (SSL). A coolant that has been heated from previous use can be conditioned by transferring heat from the coolant to a phase change medium. The conditioned coolant can then be re-used to cool the laser. In this manner, a low cost, lightweight, compact cooling system that generates comparatively quiescent flow at comparatively high flow rates can be provided.

1 . A method for cooling a solid state laser, the method comprising: 
 cooling the solid state laser with a liquid; and    using down time between laser shots to move coolant through a phase change medium heat exchanger with a blow down system so as to prepare the coolant for a subsequent round of laser cooling.    
   
   
       2 . The method of  claim 1 , wherein the coolant is stored in a first tank prior to cooling the laser and is stored in a second tank subsequent to cooling the laser.  
   
   
       3 . The method of  claim 1 , wherein the coolant is stored in a first tank prior to cooling the laser, the coolant is communicated to a second tank subsequent to cooling the laser, the coolant is cooled by transferring heat therefrom to a phase change medium after being stored in the second tank, and the coolant is communicated back to the first tank after being cooled.  
   
   
       4 . The method of  claim 1 , wherein the coolant is stored in a first tank, the coolant is cooled by transferring heat therefrom to a phase change medium prior to cooling the laser, the coolant is communicated to a second tank after cooling the laser, and the coolant is communicated back to the first tank after being communicated to the second tank.  
   
   
       5 . The method of  claim 1 , further comprising transferring heat from a phase change medium of the phase change medium heat exchanger.  
   
   
       6 . The method of  claim 1 , further comprising transferring heat from a phase change medium of the phase change medium heat exchanger via a refrigerator.  
   
   
       7 . The method of  claim 1 , further comprising using pressurized gas to urge coolant from at least one of a first tank and a second tank.  
   
   
       8 . The method of  claim 1 , further comprising using pressurized gas to urge coolant from at least one of a first and a second tank and preventing mixing of the coolant and the pressurized gas.  
   
   
       9 . The method of  claim 1 , further comprising using pressurized gas to urge coolant from at least one of a first tank and a second tank and preventing mixing of the coolant and the pressurized gas via at least one device selected from the group consisting of a diaphragm and a bladder.  
   
   
       10 . The method of  claim 1 , further comprising inhibiting sloshing of the coolant in a tank.  
   
   
       11 . The method of  claim 1 , wherein a phase change medium of the phase change medium heat exchanger comprises at least one substance selected from the group consisting of paraffin wax and Glauber salt.  
   
   
       12 . A system for cooling a solid state laser, the system comprising: 
 a phase change medium heat exchanger to which heat can be transferred from a coolant after the coolant has cooled the solid state laser; and    a blow down system for moving the coolant between the solid state laser and the phase change medium heat exchanger.    
   
   
       13 . The system as recited in  claim 12 , wherein the blow down system comprises: 
 a first coolant tank within which the coolant is stored prior to cooling the laser; and    a second coolant tank within which the coolant is stored subsequent to cooling the laser.    
   
   
       14 . The system of  claim 12 , further comprising a refrigerator for removing heat from a phase change medium of the phase change medium heat exchanger.  
   
   
       15 . The system of  claim 13 , wherein the blow down system further comprises a pressure source for pressurizing the first coolant tank and the second coolant tank, the pressure source being selected from the group consisting of a gas bottle, a gas tank, and a compressor.  
   
   
       16 . The system of  claim 13 , further comprising: 
 a first diaphragm for separating coolant from pressurized gas in the first coolant tank; and    a second diaphragm for separating coolant from pressurized gas in the second coolant tank.    
   
   
       17 . The system of  claim 13 , further comprising: 
 a first bladder for separating coolant from pressurized gas in the first coolant tank; and    a second bladder for separating coolant from pressurized gas in the second coolant tank.    
   
   
       18 . A system for cooling a solid state laser, the system comprising: 
 means for conditioning a coolant by transferring heat from the coolant to a phase change medium;    means for cooling the laser with the conditioned coolant; and    means for using pressurized gas to move the coolant between the solid state laser and the phase change medium.    
   
   
       19 . A solid state laser system comprising: 
 a solid state laser; and    a system for cooling the laser, the system comprising a phase change medium to which heat can be transferred from a coolant after the coolant has cooled the laser and a blow down system for moving the coolant between the solid state laser and the phase change medium.    
   
   
       20 . The system as recited in  claim 19 , wherein the laser comprises a high average power (HAP) solid state laser (SSL).