Temperature Sensor Using a SMF-PCF-SMF Heterostructure

Abstract

In this paper, a temperature sensor is designed and simulated using an interferometric configuration formed by inserting a photonic crystal fiber (PCF) between two single-mode fibers (SMFs). In this device, phase delay at the output is achieved by the index difference between core mode and cladding mode of PCF. In this type of interferometer, greater index difference is possible because of air-hole structure of PCF. It indicates that a small length of PCF can introduce large delay, i.e., large phase shift while keeping optical loss of the cladding mode at a relatively low level. With increase in temperature, effective refractive index difference between core and cladding of PCF decreases which results in decrease in peak output power of the interferometer. Variation of output power with temperature is observed to be linear; it is thus applicable as a temperature sensor.