Löffler T, Hahn T, Thomson M, Jacob F, Roskos H
Opt Express. 2005 Jul 11;13(14):5353-62. doi: 10.1364/opex.13.005353.
We present a detailed experimental and theoretical study of terahertz (THz) generation and beam propagation in an optoelectronic THz system consisting of a large-area (ZnTe) electro-optic emitter and a standard electro-optic detector, and provide a comparison to typical biased GaAs emitters. As predicted by theory, in the absence of saturation the generated THz pulse energy is inversely proportional to the area of the optical pump beam incident on the emitter, although the detected on-axis electric field amplitude of the subsequently focused THz beam is practically independent of this area. This latter result promotes the use of larger emitter crystals in amplifier-laser-based THz systems in order to minimize saturation effects. Moreover, the generation of an initially larger THz beam also provides improved spatial resolution at intermediate foci between emitter and detector.
我们对由大面积（ZnTe）电光发射器和标准电光探测器组成的光电太赫兹（THz）系统中的太赫兹产生和光束传播进行了详细的实验和理论研究，并与典型的偏置砷化镓发射器进行了比较。如理论所预测的，在没有饱和的情况下，所产生的太赫兹脉冲能量与入射到发射器上的光泵浦光束的面积成反比，尽管随后聚焦的太赫兹光束在轴上检测到的电场幅度实际上与该面积无关。后一个结果促进了在基于放大器 - 激光的太赫兹系统中使用更大的发射器晶体，以尽量减少饱和效应。此外，最初产生更大的太赫兹光束还能在发射器和探测器之间的中间焦点处提供更高的空间分辨率。
