Research on wideband terahertz transmission characteristics of commonly used substrate materials
Broadband transmission terahertz time-domain spectroscopy plays a significant role in research fields such as material carrier dynamics and fingerprint spectrum identification.Due to the support required for low-dimensional materials,the transmission characteristics of substrates are crucial in the study of the interaction between terahertz waves and low-dimensional materials.To investigate the optical properties of different substrate materials in the tera-hertz range,the terahertz transmission signals of three common substrate materials are tested at first.The refractive in-dex and absorption coefficient of each material are then calculated within the effective spectral range.The results show that CVD diamond maintains small-dispersion refractive index and absorption coefficients(less than 10 cm-1)in the frequency range of 1 THz~18 THz,making it suitable for use in broadband terahertz time-domain systems.While,fused quartz and magnesium oxide crystals exhibit significant dispersion in the broadband terahertz range,leading to a broadening of the transmitted time-domain signals,and they are only suitable for terahertz time-domain spectroscopy system studies in the low-frequency range(less than 3THz).Thus,the results provide an important reference for re-search based on broad-spectrum terahertz time-domain spectroscopy.