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

Grischkowsky 博士使用由超快重复激光脉冲驱动的电路，开发了一套完整的光电太赫兹光束系统，该系统可以生成和检测自由传播太赫兹辐射的 200 飞秒脉冲，时间分辨率为 65 飞秒。 基于该光电太赫兹光束系统，他开创了太赫兹时域光谱（TDS）领域。 在本提案中，他试图探索 THz-TDS 在灵敏度和动态范围方面的局限性。 需要极端动态范围的传输测量将在半导体、普通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进一步计划对分子蒸气相干太赫兹瞬变进行精确测量，并直接观察稠密蒸气中的太赫兹传播效应。

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.