REFLECTIVE FIBER OPTIC TEMPERATURE SENSOR USING SILICON THIN-FILM

We have characterized the performance of a series of fiber optic intensity sensors for temperature measurement. The method measures the change in absorption with temperature of light reflected from a thin silicon film deposited on the end of an optical fiber. Our single-ended sensing approach requires that the incident light intensity be reflected from both film surfaces and that these reflected signals reenter the fiber. Sensors fabricated with simplified methods have been shown to yield sensitivity comparable to that reported by other authors. Calibration data on sensors with different silicon film thicknesses are presented up to 400-degrees-C. Potential applications of the method are discussed.