Laser-Terahertz Emission Readout of Chemical Sensors

Author

Kiwa, T. ; Kondo, J. ; Oka, S. ; Kawayama, I. ; Yamada, H. ; Tonouchi, M. ; Tsukada, K.

Author_Institution

Okayama Univ., Okayama

fYear

2007

fDate

10-14 June 2007

Firstpage

1915

Lastpage

1918

Abstract

A new type of laser-terahertz emission system for the non-contact investigation of the chemical solutions has been developed. This system monitors the terahertz emission from a sensing plate, which consists of a silicon oxide and a silicon thin film layers on the sapphire substrate. The sensing of chemical solutions with the pH value between 1.68 and 10.01 was demonstrated. The amplitude of terahertz emission from the sensing plate increased with increasing the pH value. This change in the amplitude was caused by the change of the depletion layers of the silicon thin film when protons adsorbed at the surface of the sensing plate. This result indicates that fully non-contact monitoring of chemical solutions can be possible using the laser-terahertz emission system.

Keywords

chemical sensors; elemental semiconductors; measurement by laser beam; pH measurement; proton absorption; semiconductor thin films; silicon; silicon compounds; submillimetre wave generation; Al₂O₃; Si-SiO₂; chemical sensors; chemical solution; depletion layers; laser-terahertz emission readout; noncontact monitoring; pH sensing; protons adsorption; sapphire substrate; silicon oxide layers; silicon thin film layers; Chemical lasers; Chemical sensors; Optical pulses; Optical pumping; Optical saturation; Optical sensors; Pulse amplifiers; Semiconductor thin films; Silicon; Stimulated emission; Chemical sensor; Terahertz; Ultrafast laser;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International

Conference_Location

Lyon

Print_ISBN

1-4244-0842-3

Electronic_ISBN

1-4244-0842-3

Type

conf

DOI

10.1109/SENSOR.2007.4300533

Filename

4300533