红外非线性晶体AgGa_1-xIn_xSe₂的光学性能研究

【作者】 吴海信； 耿磊；

【机构】 中国科学院安徽光学精密机械研究所；

【摘要】 AgGa_1-xIn_xSe₂是近几年来研制的新型红外非线性光学晶体材料,其主要特点是借着Ga和In含量,即X值的变化,改变材料的折射率、双折射,实现三波共线非线性作用的非临界（90°）相位匹配。用HITA 270—30分光光度计测试了我们实验室制备的硒铟镓银(AgGa_1-xIn_xSe₂)晶体透过率;用TEA CO₂激光器成功进行了晶体元件10.6μm倍频实验,输出5.3μm的中红外激光。根据实验测得的角度调谐曲线和相位匹配角,计算了晶体中的实际In含量,比分析测得In的含量更为准确。计算了硒铟镓银(AgGa_1-xIn_xSe₂)晶体在特定波长泵浦下的Ⅰ类OPO角度调谐曲线,并分析了硒铟镓银(AgGa_1-xIn_xSe₂)晶体组份的不同X值对在特定波长泵浦下实现非临界相位匹配的影响和趋势,得出了实现非临界Ⅰ类相位匹配,输出3～12μm激光的晶体X值范围是0.224～0.3722,对进一步提高硒铟镓银(AgGa_1-xIn_xSe₂)晶体的质量和变频（OPO、DFG、SHG）实验具有指导意义。更多还原

【Abstract】 AgGa_1-xINx-INxSe₂ is a novel IR nonlinear crystal developed in recent years,its main advantage is that the reflective index and birefringence will be changed by varying the contents of gallium and indium,that is,value of x,so that the 90o noncritical phase matching（NCPM）in the three—frequency colinear nonlinear interaction can be realized. The polished crystal samples’transmission was measured by using HITA 270-30 spectrophotometer and inspected by IR microscope.By pumping the AgGa_1-xIn_xSe₂ elements for type I phase-matching second harmonic generation（SHG）with pulses from a TEA CO2 laser,doubling from 10.6μm to 5.3μm has been demonstrated successfully.The experimental phase-matching tuning characteristics were ploted and the angle phase-matching bandwidth were measured together with the theoretical calculated.The exect value of x in AgGa_1-xln_xSe₂ elements was accurately determined by phase-matching angle （θ）measured during SHG experiments. Calculating of type I phase-matching OPO has been performed at specific pump wavelength in detail.Noncritical phase-matching OPO of AgGa_1-xIn_xSe₂ with different x using different pump laser has been studied and analyzed.By changing x value（0.224-0.3722）of AgGa_1-x In_xSe₂ single crystal,we can realize type I noncritical phase-matching and yield tunable mid-to -far infrared laser light of 3～12μm,which will achieve innovational results in the crystal growth and characterization and promote a widespread applications of AgGa_1-xIn_xSe₂ crystals for OPO, DFG,SHG frequence conversion.更多还原