Elastic constants and thermal fracture of AgGaSe2 and d-LAP

The elastic constants and thermoelastic coefficients of silver gallium selenide and deuterated l-arginine phosphate (d-LAP) are reported. Their fracture strength as measured by indentation tests is also reported. These data are used to calculate their thermal fracture resistance, a parameter which is important in high-average-power laser systems. Their thermal fracture resistance is then compared to that of other nonlinear crystals. To the extent that the damage threshold increases with fracture temperature, the data on AgGaSe₂ and d-LAP are favorable indicators of a higher damage threshold. In particular, the data suggest that d-LAP should compare favorably with other solution-grown materials such as lithium iodate and KDP. Preliminary data on the damage threshold of d-LAP appear to confirm that it is indeed more damage resistant than comparably prepared samples of these other solution-grown materials