Thermo-optic coefficients and thermal lensing in Nd-doped KGd(WO_(4))_(2) laser crystals

摘要

We measured the thermo-optic coefficients dn/dT of anisotropic Nd:KGd(WO_(4))_(2) crystals at the wavelengths of 1.064 (mu)m and 532 nm (300 K) by a beam deflection method. The values of dn/dT are determined to be dn_(p)/dT velence -16.0 X 10~(-6) K~(-1), dn_(m)/dT velence -11.8 X 10~(-6) K~(-1), and dn_(g)/dT velence -19.5 X 10~(-6) K~(-1) (at 1.064 (mu)m) and dn_(p)/dT velence -14.3 X 10~(-6) K~(-1), dn_(m)/dT velence -10.0 X 10~(-6) K~(-1), and dn_(g)/dT velence -15.0 X 10~(-6) K~(-1) (at 532 nm). Thermal lensing in the flashlamp-pumped N_(p)- and N_(g)-cut Nd:KGd(WO_(4))_(2) laser rods was studied at 1.064 (mu)m by a probe beam technique in the nonlasing conditions, and the contribution of the photoelastic term to the thermal lens optical power was estimated. Athermal propagation directions with the definitions dn/dT + (n - 1)(alpha)_(T) velence 0 and dn/dT + n(alpha)_(T) velence 0 were found in Nd:KGd(WO_(4))_(2).