The use of 1.5 /spl mu/m infrared light from a cooled scintillator for optical fiber based system

The scintillation mechanism in scintillators is affected by the operating temperature. Therefore we can control to some extent the scintillation property by controlling the temperature. Recently we developed an optical fiber based radiation measurement system in a nuclear facility. To utilize the full ability of optical fibers, the wavelength of conventional scintillators is too short. Thus we investigated the scintillation property at different temperatures. After a series of experiments, we have found infrared light emission around 1.5 /spl mu/m from a cooled CsI(Tl) scintillator. Although the intensity of this emission is less than 1/10 of the visible light intensity, this wavelength matches the minimum loss in silica optical fibers. It also matches partly the amplification band of the erbium doped fiber amplifier (EDFA). This interesting coincidence might lead us to the possibility of using this material as an /spl psi/infrared scintillator".