Yostumi Yoshi

By Iwao Mizumoto, Hiroshi Oguma and Yostumi Yoshi

The spectrum of 1O2 was measured by the InGaAs photodiode for an optical communication system with charge integration amplifier (InGaAs-CIA). The photo-excited current is charged in photodiode junction capacitance itself. The current is changed to the voltage about 1012 times without feedback resistance. The minimum detectable power of InGaAs CIA system with liquid nitrogen was achieved 0.1 fW of 10 sec integration time at the wavelength of 1.28 μm. The optical band pass filter-based system for ultra–low-level light detection was succeeded in spectrum measurement of 1O2 by 13-LOOH with cytochrome c. The 8 channel InGaAs-CIA array system enables to achieve optical multichannel detection for ultra-low level light at 10−13 W from 10−15 W level in the near-infrared region. The optical resolution was about 200 nm by 1 channel. The spectrum of 1O2 by mixing NaOCl and H2O2 was demonstrated. The shape of spectrum by 1O2 was matched to that of measured by the spectrometer. The system was succeeded in instantaneous 1O2 spectrum measurement without moving the wavelength dispersion device. The generation of 1O2 by photo-excited Rose Bengal was fabricated to develop food antioxidant chemistry or source reagent of cosmetic product. The system uses super luminosity LED for excitation light source and InGaAs CIA. The 1O2 generation will be controlled by the InGaAs-CIA monitoring system. The system will be used in the chemical plant of primary material production.

Part of the book: Developments in Near-Infrared Spectroscopy