Solid-state suspension laser

Abstract

A solid-state suspension laser. The novel laser includes a gain medium comprised of a plurality of solid-state gain particles suspended in a fluid. The laser also includes a pump source for pumping the gain particles and a resonator for amplifying and outputting laser light generated by the gain medium. In an illustrative embodiment, the gain medium is adapted to flow, and the pumping of the gain medium occurs outside of the resonator. The flow velocities and the densities of the gain particles in the gain medium can be optimized for optimal absorption efficiency during the pumping and/or for optimal extraction efficiency in the resonator as well as for overall laser performance optimization, including power, efficiency and beam quality scalability.

1 . A laser gain medium comprising: 
 a fluid and    a plurality of solid-state gain particles suspended in said fluid.    
     
     
         2 . The invention of  claim 1  wherein said fluid has an index of refraction approximately matched to an index of refraction of said gain particles.  
     
     
         3 . The invention of  claim 1  wherein said fluid includes a liquid.  
     
     
         4 . The invention of  claim 1  wherein said fluid includes a cryogenically cooled liquid.  
     
     
         5 . The invention of  claim 1  wherein said gain particles are fabricated from a glass or crystalline host doped with laser gain ions.  
     
     
         6 . A laser comprising: 
 a gain medium comprised of a plurality of solid-state gain particles suspended in a fluid and    first means for pumping said gain particles.    
     
     
         7 . The invention of  claim 6  wherein said gain medium is adapted to flow.  
     
     
         8 . The invention of  claim 6  wherein said laser further includes second means for amplifying and outputting laser light generated by said gain medium.  
     
     
         9 . The invention of  claim 8  wherein said second means includes a resonator.  
     
     
         10 . The invention of  claim 9  wherein said pumping occurs outside of said resonator.  
     
     
         11 . The invention of  claim 10  wherein said laser further includes one or more pump modules for containing said gain medium during said pumping.  
     
     
         12 . The invention of  claim 11  wherein said gain medium is adapted to flow out of said pump module or modules and into said resonator.  
     
     
         13 . The invention of  claim 6  wherein said laser further includes means for adjusting the density of gain particles in said gain medium for optimal absorption efficiency during said pumping.  
     
     
         14 . The invention of  claim 9  wherein said laser further includes means for adjusting the density of gain particles in said gain medium for optimal extraction efficiency in said resonator.  
     
     
         15 . The invention of  claim 12  wherein said laser further includes means for injecting more fluid into said gain medium.  
     
     
         16 . The invention of  claim 15  wherein more fluid is injected into said gain medium after said pumping and before entering said resonator.  
     
     
         17 . The invention of  claim 12  wherein said laser further includes means for ejecting fluid from said gain medium.  
     
     
         18 . The invention of  claim 17  wherein said fluid is ejected from said gain medium after exiting said resonator.  
     
     
         19 . The invention of  claim 12  wherein said pump modules are shaped for optimal absorption efficiency during pumping.  
     
     
         20 . The invention of  claim 12  wherein said laser further includes means for controlling the flow velocity of said gain medium during pumping for optimal absorption.  
     
     
         21 . The invention of  claim 12  wherein said laser further includes third means for controlling the flow velocity of said gain medium through said resonator for optimal extraction.  
     
     
         22 . The invention of  claim 21  wherein said third means includes a volume change between said resonator and said pump module or modules.  
     
     
         23 . The invention of  claim 9  wherein said resonator is shaped to optimize extraction efficiency.  
     
     
         24 . The invention of  claim 9  wherein said resonator is shaped to match resonator modes.  
     
     
         25 . The invention of  claim 9  wherein said resonator is designed using image rotating techniques to compensate for gain non-uniformity.  
     
     
         26 . The invention of  claim 9  wherein said resonator is thin in cross-flow direction.  
     
     
         27 . The invention of  claim 9  wherein said resonator has a large aspect ratio in cross-sectional area to reduce non-uniformities in gain medium density and increase power scalability.  
     
     
         28 . The invention of  claim 6  wherein said fluid has an index of refraction approximately matched to the index of refraction of said gain particles.  
     
     
         29 . The invention of  claim 6  wherein said fluid includes a liquid.  
     
     
         30 . The invention of  claim 6  wherein said fluid includes a cryogenically cooled liquid.  
     
     
         31 . The invention of  claim 6  wherein said gain particles are fabricated from a glass or crystalline host doped with laser gain ions.  
     
     
         32 . The invention of  claim 6  wherein said first means includes an optical pump source.  
     
     
         33 . The invention of  claim 6  wherein said first means includes an array of laser diodes.  
     
     
         34 . The invention of  claim 12  wherein said laser further includes an injection mechanism for injecting said gain medium into said pump module or modules.  
     
     
         35 . The invention of  claim 12  wherein said laser further includes means for cooling said gain medium after it flows out of said resonator.  
     
     
         36 . The invention of  claim 34  wherein said laser further includes means for returning said gain medium to said injection mechanism after it flows out of said resonator.  
     
     
         37 . A laser comprising: 
 a gain medium comprised of a plurality of solid-state gain particles suspended in a fluid;    a pump source adapted to pump said gain particles; and    a resonator for amplifying and outputting laser light generated by said gain medium.    
     
     
         38 . A laser system comprising: 
 a gain medium comprised of a plurality of solid-state gain particles suspended in a fluid;    a pump source adapted to pump said gain particles;    one or more pump modules for containing said gain medium during said pumping;    an injection mechanism for injecting said gain medium into said pump module or modules;    a resonator adapted to receive said gain medium from said pump modules; and    a recycling mechanism for receiving said gain medium from said resonator and returning said gain medium to said injection mechanism.    
     
     
         39 . A method for generating laser energy including the steps of: 
 forming a gain medium comprised of a plurality of solid-state gain particles suspended in a fluid;    pumping said gain particles; and    amplifying laser energy generated by said gain medium in a resonator.    
     
     
         40 . The invention of  claim 39  wherein said method further includes flowing said gain medium through said resonator in a cross-flow direction.  
     
     
         41 . The invention of  claim 40  wherein said method further includes choosing a length of said resonator in said cross-flow direction in order to achieve a desired flow velocity.  
     
     
         42 . The invention of  claim 39  wherein said method further includes shaping said resonator in order to optimize energy extraction efficiency.  
     
     
         43 . The invention of  claim 39  wherein said method further includes adjusting a density of said gain particles in order to optimize energy extraction efficiency in said resonator.  
     
     
         44 . The invention of  claim 39  wherein said method further includes adjusting a density of said gain particles in order to optimize absorption efficiency during said pumping.