SMS fibre structure for temperature measurement using a simple intensity-based interrogation system

A singlemode-multimode-singlemode (SMS) fibre structure for temperature measurement that utilises a simple intensity-based interrogation system is proposed. The temperature dependence of the SMS fibre structure utilised as a sensor is investigated numerically and experimentally. It is found that a strong temperature dependence for the SMS fibre structure exists at selected wavelengths. The temperature characteristic at such wavelengths is linear in nature and can be used for temperature measurements. The proposed temperature sensor offers a high resolution and accuracy, and also benefits from a simple configuration and low cost when compared to other fibre-optic temperature sensors.