偏振方向对ZnTe电光THz辐射探测的影响.pdfVIP

第 23 卷第 5 期 红 外 与 毫 米 波 学 报 Vol . 23 , No . 5 2004 年 10 月 J . Infrared Millim. Waves October ,2004 ( ) 文章编号 :1001 - 9014 2004 05 - 0333 - 04 偏振方向对 Zn Te 电光 THz 辐射探测的影响 顾春明 , 　刘 　锐 , 　贺莉蓉 , 　沈文忠 (上海交通大学 物理系凝聚态光谱与光电子物理实验室 ,上海 　200030) 摘要 :在实验上研究了探测光的偏振方向对 ZnTe 晶体 THz 探测的影响. 在一周 360°范围内,测量出现两次零值 ,角 度间隔为 180°,在两个零值之间的90°处出现不为零的小值 ,45°处不为最大值. 将 ZnTe 晶体在 THz 辐射电脉冲作用 下产生的电光效应等效于瞬间任意波片 ,用琼斯矩阵法模拟实验过程 ,结果表明除在 900 处出现零值外其余模拟结 果与实验结果相符. 用 THz 光子与横光学声子相互作用模型对此进行了定性解释. 关 　键 　词 :红外物理 ;光学非线性 ;THz 辐射 ; 电光效应 ; ZnTe 晶体 中图分类号 :O47 　　文献标识码 :A EFFECTS OF PROBEBEAM POLARIZATION DIRECTION ON THz DETECTION IN Zn Te GU ChunMing , 　L IU Rui , 　HE LiRong , 　SHEN WenZhong (Laboratory of Condensed Matter Spectroscopy and OptoElectronic Physics , Department of Physics , Shanghai Jiao Tong University , Shanghai 200030 , China) Abstract :The effects of probebeam polarization direction on the THz detection in ZnTe were investigated experimentally. By keeping the THz radiation intensity unchanged , we observed two minimums with an interval of 1800 when the direction of the θ probebeam polarization was changed from 0 to 360°. Nonzero THz radiation was detected in the middle of the two minimums ( θ ) = 90°. The Jones Matrix method was employed to simulate the experiments by assuming the electrooptic effect in ZnTe under a THz field as an equivalent arbitrary wave plate . It was found that all the simulation results were in agreement with the experi ments , e