TEMPERATURE SENSITIVITY OF PHASE-MATCHED 2ND-HARMONIC GENERATION IN LIIO3

We have measured the temperature dependence (between 23 and 65°C) of the phase-matching angle θpm for type I frequency doubling of 1064 nm laser light in lithium iodate (LiIO3). The measured value of dθpm/dT is − 14.7 ± 1 μrad/°C, which corresponds to a thermal sensitivity βT = 0.24 ± 0.02 cm−1/°C for this process. We have also calculated a value for dθpm/dT using experimentally determined thermooptic data available in the literature. The calculated value of dβpm/dT is −31 ± 18 μrad/°C using literature values of n and dn/dT for LilO3. We suspect that the extreme sensitivity of the calculated value of dβpm/dT to small errors in the thermooptic coefficients is the reason for this discrepancy. © 1990 IEEE