[16a-P05-1~16] 3.8 Terahertz technologies

[16a-P05-16] Apparent Change in Transmittance by THz-TDS with Sample-Insertion into the THz-Beam Focus

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

When a sample is inserted into the electromagnetic wave focusing section of a terahertz time-domain spectroscopy system, the measured transmittance and phase shift exhibit slight differences compared to results obtained from parallel-section measurements. Previously, we proposed two semi-analytical calculation methods using the complex parameters of Gaussian beam optics. However, these methods either neglected the wavefront curvature of THz waves or contained calculation errors. In this report, we present an improved calculation method that accounts for the wavefront curvature, based on the inner product of Gaussian-shaped radiation and detection patterns. Additionally, we compare and evaluate this method against measurement results, such as amplitude transmittance.