中文摘要：

利用太赫兹（THz）光参量发生器,测量了KTP晶体和KTA晶体在3-6THz波段的折射率。利用一束脉冲宽为5ns的Nd：YAG 1 064nm激光作为泵浦源,分别泵浦KTP晶体和KTA晶体,获得了一束宽谱的Stokes光;测量了泵浦光和产生的Stokes光的非共线相位匹配角度以及对应Stokes光的波长,通过计算得出了KTP晶体在3.07-6.12THz波段对应的折射率为2.81-5.05;KTA晶体在3.71-6.19THz波段对应的折射率为3.26-4.68。

英文摘要：

KTiOPO4 （KTP） and KTiOAsO4 （KTA） crystals are new media to generate terahertz （THz） waves. In this paper,a method for measuring the refractive index of KTP and KTA crystals at 3-6 THz is demonstrated. The Stokes light with wide spectrum was obtained, using an Nd：YAG 1064 nm laser as pump source and a KTP （KTA） crystal as the nonlinear medium in the terahertz-wave parametric generation. The 1064 nm laser has a pulse width of 5 ns and a pulse repetition rate of 1 Hz. The crystals with dimensions of 5 mm× 5 mm× 20 mm are cut at an x axis. Using a collimator,the diameter of 1 064 nm laser is converted to 1.5 mm. The Stokes wavelengths and the corresponding angle between pump and Stokes waves are measured. The refractive index of KTP crystal is calculated to be 2.81-5.05 at 3.07-6.12 THz,and the refractive index of KTA crystal is calculated to be 3. 2644.68 at 3.71-6.19 THz.