Temperature measurement using thermal radiation from SiO/sub 2/ doped with rare-earth elements

Thermal radiation from SiO/sub 2/ fibers doped with rare-earth elements were studied for a fiber-optic thermometer application at high temperatures. Thermal radiation similar to black body radiation was observed in the visible light region from SiO/sub 2/ fibers doped with Y. Thermally excited visible light radiation peaks due to f-f transitions of rare-earth ions were clearly observed in the SiO/sub 2/ fibers doped with Er. Temperature dependence of the thermal radiation intensity of the rare-earth doped SiO/sub 2/ fiber is potentially useful for temperature measurement in the high temperature region above about 900 K.