Title :
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
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;
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
DOI :
10.1109/SENSOR.2007.4300533
