Fundamental Research on All Optical Submillimeter Wave Generation and Detection System

利用介质和半导体材料中的非线性光学过程产生亚毫米波已经得到了广泛的研究。主要研究结果总结如下：1.研究成果。利用周期极化LiNbO_3和LiTaO_3.2，提出并模拟了准相位匹配的非线性相互作用产生亚毫米波。某些半导体材料(GaAs、InP、CDS)在近红外激光泵浦的SMW的参数振荡中具有相位匹配的可能性。利用GaAs计算了单谐振子下的阈值功率密度。从理论上计算了基于反对称子带的AlGaAsGaAs二阶非线性极化率。发现它比大块晶体大两个数量级。对具有子带间和子带内分裂能跃迁的耦合量子阱进行了计算。

Submillimeter-wave generations utilizing nonlinear optical processes in dielectric and semiconductor materials have been extensively studied. Main results are summarized as follows.1. Quasi-phase matched nonlinear interactions to generate submillimeter-waves (SMW) are proposed & simulated using periodically poled LiNbO_3 and LiTaO_3.2. Some semiconductor materials (GaAs, InP,CdS) possess the possibility of phasematching for the parametric oscillation of SMW pumped at near infrared laser. Threshold power density was calculated under the singly resonant oscillator using GaAs.3. The second order nonlinear susceptibility based on the intersubband of anti-symmetric quantum well was calculated theoretically for AlGaAs-GaAs. It was found to be two-orders larger than that of bulk crystal. Calculations for the coupled quantum well having splitting energy transition of inter and intra-subband were also performed.