Chemical sensing plate with a laser-terahertz monitoring system

A new type of laser-terahertz emission system for noncontact investigations of chemical solutions has been developed. The system monitors terahertz emission from a sensing plate, which consists of silicon oxide and silicon thin film layers on a sapphire substrate. Sensing of chemical solutions with...

Full description

Saved in:
Bibliographic Details
Published inApplied optics (2004) Vol. 47; no. 18; p. 3324
Main Authors Kiwa, Toshihiko, Kondo, Junichi, Oka, Shohei, Kawayama, Iwao, Yamada, Hironobu, Tonouchi, Masayoshi, Tsukada, Keiji
Format Journal Article
LanguageEnglish
Published United States 20.06.2008
Online AccessGet more information

Cover

More Information
Summary:A new type of laser-terahertz emission system for noncontact investigations of chemical solutions has been developed. The system monitors terahertz emission from a sensing plate, which consists of silicon oxide and silicon thin film layers on a sapphire substrate. Sensing of chemical solutions with pH values between 1.68 and 10.01 was demonstrated. The amplitude of the terahertz emission from the sensing plate increased with increasing pH value. This change in the amplitude was caused by a change in the depletion layers of the silicon thin film when protons were adsorbed on the surface of the sensing plate. This study demonstrates that full noncontact monitoring of chemical solutions is possible using the laser-terahertz emission system.
ISSN:1559-128X
DOI:10.1364/AO.47.003324