Method and apparatus for pulsed harmonic ultraviolet lasers

Abstract

An apparatus for producing coherent, pulsed ultraviolet light with pulse durations that range between 1 ps and 1 μs includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more FC stages, at least one of the one or more FC stages including a nonlinear FC device and one or more optical elements. The optical elements include a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component. The FC device includes a huntite-type aluminum double borate nonlinear optical material configured to produce FC light having a wavelength between 190 and 350 nm and a composition given by RAl 3 B 4 O 12 , where R comprises one or a plurality of elements {Sc, La, Y, Lu}. The nonlinear optical material is characterized by an optical transmission greater than 70% over the wavelength range of 190 to 350 nm.

1 . An apparatus for producing coherent, pulsed, ultraviolet light, the apparatus comprising:
 one or more source lasers configured to provide visible or near-infrared output radiation; and   one or more frequency conversion stages, at least one of the one or more frequency conversion stages including a nonlinear frequency conversion device and one or more optical elements including: a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component; and   wherein the nonlinear frequency conversion device includes a nonlinear optical material producing frequency converted light having a wavelength between 190 and 350 nm and experiences a local peak intensity greater than 5 GW/cm 2  during operation.   
     
     
         2 . The apparatus of  claim 1  wherein the frequency converted light is output light of the apparatus. 
     
     
         3 . The apparatus of  claim 1  wherein the local peak optical intensity ranges from about 5-10 GW/cm 2 . 
     
     
         4 . The apparatus of  claim 1  wherein the local peak optical intensity ranges from about 10-20 GW/cm 2 . 
     
     
         5 . The apparatus of  claim 1  wherein the local peak optical intensity ranges from about 20-30 GW/cm 2 . 
     
     
         6 . The apparatus of  claim 1  wherein the local peak optical intensity ranges from about 30-50 GW/cm 2 . 
     
     
         7 . The apparatus of  claim 1  wherein the local peak optical intensity is greater than 50 GW/cm 2 . 
     
     
         8 . The apparatus of  claim 1  wherein the nonlinear frequency conversion device comprises a huntite-type aluminum double borate material having a composition given by RAl 3 B 4 O 12 , where R is one or a plurality of elements {Sc, La, Y, Lu}. 
     
     
         9 . The apparatus of  claim 8  wherein the composition is given by
 Y (1-x) La x Al 3 B 4 O 12 , with 0≦x≦0.4. 
 
     
     
         10 . The apparatus of  claim 9  wherein x is about 0.25. 
     
     
         11 . The apparatus of  claim 9  wherein x=0. 
     
     
         12 . The apparatus of  claim 8  wherein the composition is given by
 Lu (1-x) La x Al 3 B 4 O 12 , with 0≦x≦0.4. 
 
     
     
         13 . The apparatus of  claim 1  wherein the one or more source lasers comprises a single source laser having a nominal angular frequency w and wherein an output of the apparatus includes one or more of nominal angular frequencies: 2ω, 3ω, 4ω, 5ω, 6ω, 7ω, or 8ω. 
     
     
         14 . An apparatus for producing coherent, pulsed, ultraviolet light, the apparatus comprising:
 one or more source lasers with visible or near-infrared output radiation; and   one or more frequency conversion stages, at least one of the one or more frequency conversion stages including a nonlinear frequency conversion device and one or more optical elements including: a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component; and;   wherein the nonlinear frequency conversion device includes a nonlinear optical material configured to produce frequency converted light having a wavelength between 190 and 350 nm, and wherein the nonlinear optical material operates with a time-averaged local optical intensity greater than about 50 MW/cm 2 .   
     
     
         15 . The apparatus of  claim 14  wherein the time-averaged local optical intensity ranges from about 50-100 MW/cm 2 . 
     
     
         16 . The apparatus of  claim 14  wherein the time-averaged local optical intensity ranges from about 100-250 MW/cm 2 . 
     
     
         17 . The apparatus of  claim 14  wherein the time-averaged local optical intensity ranges from about 250-500 MW/cm 2 . 
     
     
         18 . The apparatus of  claim 14  wherein the time-averaged local optical intensity is greater than about 500 MW/cm 2 . 
     
     
         19 . The apparatus of  claim 14  wherein the frequency converted light is output light of the apparatus. 
     
     
         20 . An apparatus for producing coherent, pulsed, ultraviolet light, the apparatus comprising:
 one or more source lasers emitting radiation in the visible or near-infrared frequency range;   one or more frequency conversion stages, at least one of the one or more frequency conversion stages including a nonlinear frequency conversion device configured to receive light propagating along an optical path passing through the nonlinear frequency conversion device and one or more optical elements including: a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component, wherein the nonlinear frequency conversion device includes:
 a thermally-conducting mount having a first side, a second side opposing the first side and a passage extending from the first side to the second side, wherein the passage defines a mounting surface; 
 a nonlinear optical device having opposing facets having a component perpendicular to the propagation axis and an exterior surface extending between the opposing facets at a periphery of the nonlinear optical crystal, the nonlinear optical crystal being mounted in the thermally-conducting mount; and 
 a solder containing a metal material disposed between the mounting surface of the thermally-conducting mount and the exterior surface of the nonlinear optical crystal. 
   
     
     
         21 . The apparatus of  claim 20  wherein the nonlinear optical crystal produces frequency converted light having a wavelength between 190 and 350 nm, and wherein the nonlinear optical crystal experiences an average optical intensity greater than 50 MW/cm 2  during operation. 
     
     
         22 . The apparatus of  claim 20  wherein the solder makes contact with an entirety of the mounting surface of the thermally-conducting mount and an entirety of the exterior surface of the nonlinear optical crystal. 
     
     
         23 . The apparatus of  claim 20  further comprising a water or solvent soluble wetting or fluxing agent, wherein the solder is characterized by a melting point below 900 K. 
     
     
         24 . The apparatus of  claim 20  wherein the nonlinear optical crystal comprises a huntite-type aluminum double borate material having a composition given by RAl 3 B 4 O 12 , where R is one or a plurality of elements {Sc, La, Y, Lu}. 
     
     
         25 . The apparatus of  claim 24  wherein the composition is given by
 Y (1-x) La x Al 3 B 4 O 12 , with 0≦x≦0.4. 
 
     
     
         26 . The apparatus of  claim 25  wherein x is about 0.25. 
     
     
         27 . The apparatus of  claim 25  wherein x=0. 
     
     
         28 . The apparatus of  claim 24  wherein the composition is given by
 Lu (1-x) La x Al 3 B 4 O 12 , with 0≦x≦0.4.