Terahertz Spectroscopic Techniques for Material Characterization and Source Development

Terahertz spectroscopy has become a powerful tool in physical, chemical and biological researches. Traditional terahertz spectroscopic techniques can be divided into six categories, including Fourier transform infrared spectroscopy, time-domain spectroscopy, directly tuning frequency, heterodyne mixing/photomixing, dispersive optics and narrowband filter array. In this work, we will first give an overview on the principle, performance characteristics and applications of these techniques. It will be concluded that they have certain limitations in terms of applicability, measurement speed, etc., especially for the investigation of terahertz radiation sources, where there is a lack of convenient, compact and low-cost direct measurement and characterization method of the emission spectrum. Then we will envisage and discuss a concept of computational terahertz spectrometer.