Fiber-optic thermometer using Cr-doped YAlO3 sensor head

Cr-doped YAlO3 phosphor crystals have been grown and characterized for applications in fiber-optic thermometers based on the temperature dependence of the photoluminescence (PL) lifetime. PL peaking at lambda=735 nm is observed from the crystals following an excitation by a light-emitting diode at lambda=520 nm. Long PL lifetime (tau=43.14 ms) is observed from Cr-doped YAlO3 at room temperature as compared with those of ruby (tau=4.2 ms) and spinel (tau=8.0 ms). The temperature coefficient (-0.075 ms/K) of Cr-doped YAlO3 is also larger than those of ruby (-0.010 ms/K) or spinel (-0.037 ms/K). YAlO3 is considered to be a sensitive sensor head material for fiber-optics thermometers. (C) 2003 American Institute of Physics.