PROPERTIES OF CRLISRALF6 CRYSTALS FOR LASER OPERATION

We have performed several physical and optical measurements on the Cr: LiSAF (LiSrAlF6) laser material that are relevant to its laser perform ance, including thermal and mechanical properties, water durabilities, and Auger upconversion constants. The expansion coefficient, Young's modulus, fracture toughness, thermal conductivity, and heat capacity a re all used to determine an overall thermomechanical figure of merit f or the crystal. An investigation of the water durability suggests that the cooling solution should be maintained at pH = 7 to ameliorate pro blems associated with water dissolution. The Auger constant was found to become much more significant at higher Cr doping, in which excited- state migration leads to a substantial increase in the upconversion ra te. We propose a design for a 50-W Cr:LiSAF laser system that is based on a detailed knowledge of all the relevant material parameters.