Temperature sensitivity investigation of tapered plastic optical fiber-Mach Zehnder interferometer for sensor application

Abstract

Mach Zehnder interferometer (MZI) based on plastic optical fiber (POF) is interesting due to its robustness and simple fabrication. In this work, MZI-POF was designed and its sensitivity to temperature change was characterized to investigate its performance for sensor application. The MZI-POF was fabricated by forming two tapers at several distance by simple heat-pull method. The spectra was investigated by launching white light emitting diode (LED) and the output were observed using VIS-NIR spectrometer. It is shown that the wavelength of spectrum peak and spectrum dip were shifted compared to that of un-tapered POF which indicates that the structure serves well as MZI. Sensor sensitivity to temperature was determined by measuring the spectrum for various temperature which was varied from 40°C to 80°C with increment of 5°C. The result showed that the sensor sensitivity is 0.0693nm/°C in terms of peak measurement and 0.0487nm/°C for dip measurement. Therefore, MZI-POF is a potential candidate for temperature sensor.