[24p-P07-1~7] 3.9 Terahertz technologies

[24p-P07-5] Correction of Refractive Indices Obtained by THz-TDS with Samples at Focus

〇Osamu Morikawa¹, Ai Hattori¹, Kohji Yamamoto², Kazuyoshi Kurihara², Takashi Furuya², Fumiyoshi Kuwashima³, Masahiko Tani² (1.JCG Acad., 2.Univ. Fukui, 3.FUT)

Keywords:THz-TDS, focusing, refractive index

To obtain a complex refractive index of a sample by using the THz time-domain spectroscopic system, the output signals with and without the sample placed in the THz beam path are compared. In the case that the sample is small, it must be placed at the THz beam focus between paraboloidal mirrors. If the sample is a uniform large plate, the refractive index obtained with the sample at the THz beam focus can be compared to that obtained with the sample in the parallel THz beam. It has been reported that the former is different from the latter and can be corrected using the data obtained with the detector shift corresponding to the detector-focus shift of the THz beam caused by the sample insertion. In this report, authors propose a simpler correction method without the detector shift.