Presentation Information
[23a-P03-12]Consideration of Multiple Reflections and Beam Size in Focused-Beam THz-TDS
〇Osamu Morikawa1, Ryohei Mitsuhashi1, Taisei Yoshimoto1, Kohji Yamamoto2, Kazuyoshi Kurihara2, Takashi Furuya2, Fumiyoshi Kuwashima3, Hideaki Kitahara2, Masahiko Tani2 (1.JCGA, 2.Univ. Fukui, 3.FUT)
Keywords:
THz-TDS,focusing,refractive index
Terahertz time-domain spectroscopic systems (THz-TDSs) are broadly used for sample characterization in the THz region. If one can prepare only a small sample, it must be placed at the focus of the THz beam. In such cases, complex refractive indices obtained by applying the parallel-beam-insertion calculation method are a little bit different from the correct ones and must be corrected. In the proceeding report, we have proposed a calculation method to obtain the precise real part of the complex refractive index, in which multiple reflection effects were ignored. In the present report, we propose a semi-analytical method considering multiple reflection effects and beam-size-variation effects. This method was applied to the focused-beam-insertion data using a 9.629-mm thick polyvinyl chloride plate and rather good results were obtained.