A requirement to measure' temperature' in 1.2 Tesla magnetic fields by a. reliable, low resolution, permanently calibrated instrument. has led to the development of an all-dielectric sensor'. It is composed. of fiber optic communication line, gradient index lenses and a temperature sensitve narrow band-pass, interference filter. The spectral location of the filter passband is temperature dependent and was observed, as a large modulation of transmitted laser power on the filter edge. The resolution of a. sensor based on the spectral mean of transmitted light was better than 5 degrees celsius from 20 to 150 degrees celsius. A. line source in a. wavelength region away from the filter resonance is used for continuous spectrometer calibration. The multiplexing of sensors, is described.
"Fiber Optic-Thin Film Temperature Sensor.", Proc. SPIE 0566, Fiber Optic and Laser Sensors III, (3 January 1986); doi: 10.1117/12.949806; https://doi.org/10.1117/12.949806