Cesium-lithium-borate crystal and its application to frequency conversion of laser light

Abstract

The present invention provides a cesium-lithium-borate crystal, which can be used as a high-performance wavelength converting crystal, having a chemical composition expressed as CsLiB6O10, and substituted cesium-lithium-borate crystals expressed by the following formula: Cs 1−x Li 1−y M x+y B 6 O 10 or Cs 2(1−z) Li 2 L z B 12 O 20 (where, M is an alkali metal element, and L is an alkali earth metal element); a method for manufacturing same by heating and melting; and an optical apparatus using such crystals.

What is claimed is:  
     
         1 . A cesium-lithium-borate crystal having a chemical composition expressed as CsLiB 6 O 10 .  
     
     
         2 . A substituted cesium-lithium-borate crystal having a chemical composition expressed by the following formula:  
       Cs 1−x Li 1−y M x+y B 6 O 10   
       (where, M is at least one alkali metal element other than Cs and Li, and x and y satisfy the relationship of 0≦x≦1 and 0≦y≦1, and x and y never take simultaneously a value of 0 or 1).  
     
     
         3 . A substituted cesium-lithium-borate crystal having a chemical composition expressed by the following formula:  
       Cs 2(1−z) Li 2 L z B 12 O 20   
       (where, L is at least one alkali earth metal element, and 0<z<1).  
     
     
         4 . A crystal as claimed in  claim 1 , at least one alkali metal ion other than Cs and Li is added for improving of optical and mechanical properties.  
     
     
         5 . A crystal as claimed in  1 , at least one alkali earth metal ion is added for improving of optical and mechanical properties.  
     
     
         6 . A method for manufacturing a crystal as claimed in any one of  claims 1  to  5 , which comprises the step of heating and melting a raw material mixture of constituent elements, thereby manufacturing said crystal.  
     
     
         7 . A method for manufacturing the crystal as claimed in any one of  claims 1  to  5 , which comprises the step of growing the crystal by the melt method.  
     
     
         8 . A method for manufacturing the crystal as claimed in any one of  claims 1  to  5 , which comprises the step of growing the crystal by the flux method.  
     
     
         9 . A frequency converting apparatus which is provided with any of the crystals as claimed in  claims 1  to  5  as optical means.  
     
     
         10 . An apparatus as claimed in  claim 9  for generating the second, third, fourth or fifth harmonic of a laser.  
     
     
         11 . An optical parametric oscillator which is provided with any of the crystals as claimed in  claims 1  to  5  as optical means.