Limits and Applications of THz Time-Domain Spectroscopy and THz Coherent Transients

使用由超快重复激光脉冲驱动的电路，Grischkowsky博士开发了一个完整的光电太赫兹光束系统，该系统可以产生和检测200 fsec的自由传播太赫兹辐射脉冲，时间分辨率为65 fsec。基于这一光电太赫兹波束系统，他开创了太赫兹时域光谱（TDS）的研究领域。在这个提案中，他试图探索太赫兹- tds在灵敏度和动态范围方面的限制。需要极端动态范围的传输测量将在半导体、正常和超导金属薄膜以及热样品、火焰和等离子体等样品上进行。PI进一步计划精确测量来自分子蒸气的相干太赫兹瞬变，并直接观察通过密集蒸气的太赫兹传播效应。

Using circuitry which is driven by ultrafast repetitive laser pulses, Dr. Grischkowsky has developed a complete optoelectronic THz beam system which can generate and detect 200 fsec pulses of freely propagating THz radiation with a time resolution of 65 fsec. Based on this optoelectronic THz beam system, he has pioneered the field of THz time- domain spectroscopy (TDS). In this proposal he seeks to explore the limits of THz-TDS with respect to both sensitivity and dynamic range. Transmission measurements requiring extreme dynamic range will be performed on samples such as semiconductors and normal and superconducting metal films as well as hot samples, flames and plasmas. The PI further plans the precise measurement of coherent THz transients from molecular vapors and the direct observation of THz propagation effects through dense vapors.