Zhang Liangliang, Zhong Hua, Mu Kaijun, Zhang Cunlin, Zhao Yuejin
Beijing Key Lab for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, No.105 XiSanHuan BeiLu, Beijing, 100048, China.
Opt Express. 2012 Jan 2;20(1):75-80. doi: 10.1364/OE.20.000075.
We present a theoretical and experimental investigation of the THz pulse phase measured by a broadband heterodyne detection method via field-induced second-harmonic generation in ambient air. The dependence of the detected THz phase spectra on the positions of the wire shaped electrodes scanning along the detection plasma is discussed. An additional phase shift around the beam focus is observed. Theoretical deductions reveal that it is caused by the Gouy shift of the optical probe beam and THz beam during the heterodyne detection process.
我们通过在环境空气中利用场致二次谐波产生的宽带外差检测方法，对太赫兹（THz）脉冲相位进行了理论和实验研究。讨论了检测到的太赫兹相位谱对沿检测等离子体扫描的线状电极位置的依赖性。观察到光束焦点周围存在额外的相移。理论推导表明，这是由外差检测过程中光学探测光束和太赫兹光束的古依相移引起的。
