@inproceedings{ecb05c7a7560412bab0cf6f7515cb3e7,
title = "Terahertz gas sensing based on time-domain-spectroscopy using a hollow-optical fiber gas cell",
abstract = "Terahertz gas sensing system based on time-domain spectroscopy (THz-TDS) using a hollow-optical fiber gas cell is proposed. A hollow optical fiber functions as a long-path and low-volume gas cell and loading a dielectric layer on the inside of the fiber reduces the transmission loss and the dielectric layer also protects the metal layer of the fiber from deterioration. In the fabrication process, a polyethylene tube with a thin wall is drawn from a thick preform and a metal layer is formed on the outside of the tube. By using a 34-cm long fiber gas cell, NH3 gas with a concentration of 8.5 % is detected with a good SN ratio. However, the absorption peaks of NH3 and water vapor appeared at around 1.2 THz are not separated. To improve the frequency resolution in Fourier transformation, the time scan width that is decided by the scanning length of linear stage giving a time delay in the probing THz beam is enlarged. As a result, the absorption peaks at around 1.2 THz are successfully separated. In addition, by introducing a longer fiber gas cell of 60-cm length, the measurement sensitivity is improved and an absorption spectrum of NH3 gas with a concentration of 0.5 % is successfully detected.",
keywords = "Breath analysis, Hollow optical fiber, Terahertz waveguide, Time domain spectroscopy",
author = "T. Suzuki and T. Katagiri and Y. Matsuura",
note = "Publisher Copyright: Copyright {\textcopyright} 2018 SPIE.; Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII 2018 ; Conference date: 27-01-2018 Through 28-01-2018",
year = "2018",
doi = "10.1117/12.2288102",
language = "英語",
series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
publisher = "SPIE",
editor = "Israel Gannot and Israel Gannot",
booktitle = "Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVIII",
}