Tomasino A, Parisi A, Stivala S, Livreri P, Cino A C, Busacca A C, Peccianti M, Morandotti R
DEIM, University of Palermo, Viale delle Scienze Bldg. 9, 90128, Palermo, Italy.
Sci Rep. 2013 Oct 31;3:3116. doi: 10.1038/srep03116.
We present an analytical model describing the full electromagnetic propagation in a THz time-domain spectroscopy (THz-TDS) system, from the THz pulses via Optical Rectification to the detection via Electro Optic-Sampling. While several investigations deal singularly with the many elements that constitute a THz-TDS, in our work we pay particular attention to the modelling of the time-frequency behaviour of all the stages which compose the experimental set-up. Therefore, our model considers the following main aspects: (i) pump beam focusing into the generation crystal; (ii) phase-matching inside both the generation and detection crystals; (iii) chromatic dispersion and absorption inside the crystals; (iv) Fabry-Perot effect; (v) diffraction outside, i.e. along the propagation, (vi) focalization and overlapping between THz and probe beams, (vii) electro-optic sampling. In order to validate our model, we report on the comparison between the simulations and the experimental data obtained from the same set-up, showing their good agreement.
我们提出了一个分析模型，用于描述太赫兹时域光谱（THz-TDS）系统中的全电磁传播，从通过光整流产生太赫兹脉冲，到通过电光采样进行检测。虽然已有多项研究分别探讨了构成太赫兹时域光谱系统的诸多元件，但在我们的工作中，我们特别关注对构成实验装置的所有阶段的时频行为进行建模。因此，我们的模型考虑了以下主要方面：（i）泵浦光束聚焦到产生晶体中；（ii）产生晶体和检测晶体内部的相位匹配；（iii）晶体内部的色散和吸收；（iv）法布里-珀罗效应；（v）外部衍射，即沿传播方向的衍射；（vi）太赫兹光束和探测光束之间的聚焦和重叠；（vii）电光采样。为了验证我们的模型，我们报告了模拟结果与从同一装置获得的实验数据之间的比较，结果表明二者吻合良好。
