Intrinsic optical fiber temperature sensor based on the differential absorption technique

A microprocessor‐based instrument for temperature measurement has been developed based upon the intrinsic temperature sensitive absorption properties of a neodymium doped optical fiber. The accuracy and repeatability of temperature measurement are investigated with respect to the stability of environmentally sensitive system components. In the light of these investigations a prototype instrument employing novel compensation techniques has been developed. Accuracy and repeatability have been determined to be better than ±1 °C over a 20–200 °C temperature measurement range with the potential of increased range and accuracy for temperatures down to −100 °C.