Loiko Pavel A, Yumashev Konstantin V, Kuleshov Nikolai V, Pavlyuk Anatoly A
Center for Optical Materials and Technologies, Belarusian National Technical University, 65 Nezavisimosti Avenue, Building 17, Minsk, Belarus 220013.
Appl Opt. 2010 Dec 1;49(34):6651-9. doi: 10.1364/AO.49.006651.
We measured the thermo-optic coefficients dn/dT of anisotropic Nd:KGd(WO(4))(2) crystals at the wavelengths of 1.064 μm and 532 nm (300 K) by a beam deflection method. The values of dn/dT are determined to be dn(p)/dT = -16.0 × 10(-6) K(-1), dn(m)/dT = -11.8 × 10(-6) K(-1), and dn(g)/dT = -19.5 × 10(-6) K(-1) (at 1.064 μm) and dn(p)/dT = -14.3 × 10(-6) K(-1), dn(m)/dT = -10.0 × 10(-6) K(-1), and dn(g)/dT = -15.0 × 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 μm 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)α(T) = 0 and dn/dT + nα(T) = 0 were found in Nd:KGd(WO(4))(2).
我们采用光束偏转法，在波长1.064μm和532nm（300K）下测量了各向异性Nd:KGd(WO₄)₂晶体的热光系数dn/dT。在1.064μm处，dn/dT的值确定为dn(p)/dT = -16.0×10⁻⁶K⁻¹，dn(m)/dT = -11.8×10⁻⁶K⁻¹，dn(g)/dT = -19.5×10⁻⁶K⁻¹；在532nm处，dn(p)/dT = -14.3×10⁻⁶K⁻¹，dn(m)/dT = -10.0×10⁻⁶K⁻¹，dn(g)/dT = -15.0×10⁻⁶K⁻¹。通过探针光束技术，在非激光条件下，于1.064μm波长对闪光灯泵浦的N(p)-和N(g)-切割Nd:KGd(WO₄)₂激光棒中的热透镜效应进行了研究，并估算了光弹性项对热透镜光焦度的贡献。在Nd:KGd(WO₄)₂中发现了满足dn/dT + (n - 1)α(T) = 0和dn/dT + nα(T) = 0定义的无热传播方向。
