Research on fiber optic temperature sensor using a novel high-birefringent fiber loop mirror with a reflection probe

Based on the two structures of the high-birefringent fiber loop mirror (Hi-Bi FLM) with reflection probe, the relevant principles are carried out and experiments are performed to prove the principles. Temperature properties of one structure, known as the FLM with the Hi-Bi reflection probe, are experimentally studied. The temperature sensitivity is 1.698 nm/°C with good linearity, thus the temperature resolution can reach the scale of 0.04 °C in theory if the resolution of the optical spectrum analyzer (OSA) is 0.02 nm. Besides, the temperature range can be tuned by different length or birefringence of the Hi-Bi fiber. Since the reflection probe is one output of the Hi-Bi FLM, the structure can be used for the high sensitivity remote temperature sensing.

► A new fiber sensor structure was proposed based on the high-birefringent fiber loop mirror with reflection probe. ► The relevant principles are carried out and experiments are performed to prove the principles of the new structure. ► This kind structure is useful for the high sensitivity remote temperature sensing. ► The temperature sensitivity is 1.698 nm/°C with good linearity, thus the temperature resolution can reach the scale of 0.04 °C in theory if the resolution of the optical spectrum analyzer (OSA) is 0.02 nm. ► Besides, the temperature range can be tuned by different length or birefringence of the Hi-Bi fiber.