HIGH ACCURACY OPTICAL BISTABLE INTERFEROMETRIC FIBER SENSORS

Abstract

A novel optical fiber sensing technique for length and temperature measurement with accuracy of sub-nanometer and 10-4° C , respectively, is proposed. The new kind of sensor is a combination of a conventional interferometric sensor and a hybrid optical bistable device. The measurement is accomplished by counting the number of electrical pulses, provided by switching on and switching off of the optical bistability periodically. An optical bistable fiber sensor with a March–Zehnder interferometer is analyzed in this paper. The main advantages of this technique lie in the adjustable high accuracy and ability to distinguish the variation direction of quantities to be measured.