Numerical Simulation of Terahertz Wave Generation in AgGaS2 Crystal Based on CO2 Laser
基于CO2激光的AgGaS2差频产生太赫兹波的数值分析

Using a mid-infrared CO2 laser in terahertz difference frequency generation (THz-DFG) is an effective method for improving conversion efficiency and output power. According to the three-wave interaction of difference frequency, the AgGaS2 crystal is analyzed theoretically. The angle tunable curves of difference-frequency-generated THz wave under both oeo-type and oee-type phase matching conditions are simulated numerically. The walk-off angle and acceptable parameter of light wave in the crystal are calculated. In addition, the effective nonlinear coefficient and theoretical power conversion efficiency of the crystal are taken into account. The research result shows that the AgGaS2 crystal is suitable for widely tunable THz-DFG with a CO2 laser.