Construction of sub-terahertz spectroscopic system using incoherent light source

本研究的目的是利用紧凑、廉价的非相干光源构建亚太赫兹光谱系统，并证明其实用性。首先，我们构建了一个由连续波多模激光二极管（CWMLD）和低温生长GaAs （LT-GaAs）光导开关组成的系统，该开关作为亚太赫兹发射器，以及马丁-普雷特型干涉仪和测热计。通过测量掺杂硅片的透光率，验证了该系统的有效性。接下来，我们构建了一个新的光谱系统，该系统由一个CWMLD和两个光导开关组成，分别用作发射器和探测器。通过测量掺杂硅片的复折射率，证明了这种廉价紧凑的系统与使用昂贵的超短激光器的系统是等效的。

The purpose of this study is to construct sub-terahertz spectroscopic system using a compact and cheap incoherent light source and to demonstrate its usefulness. First, we constructed a system composed of a continuous wave multimode laser diode (CWMLD) and a low-temperature-grown GaAs (LT-GaAs) photoconductive switch, which work as an sub-THz emitter, and a Martin-Puplett type interferometer and bolometer. The usefulness of the system was verified by measuring transmittance of doped silicon wafers. Next, we constructed new spectroscopic system consisting of a CWMLD and two photoconductive switches, which are used for an emitter and a detector. By measuring the complex refractive index of doped silicon wafers, it is proved that this cheep and compact system is equivalent with a system using an expensive ultrashort laser.