High sensitivity temperature sensor based on liquid filled hole-assisted dual-core fiber.

A high sensitivity temperature sensor is numerically and experimentally investigated in liquid filled eccentric hole-assisted dual-core fiber (EHADCF). The sensor is constructed by cascading two single mode fibers (SMFs) with an intermediate liquid filled EHADCF segment. The light couples periodically between the center and suspended cores due to small core distance. Refractive index (RI) matching liquid with high thermo-optic coefficient is filled into the air-hole of the EHADCF as the cladding of the suspended core. The dispersion curves of the center and suspended cores of the EHADCF change with the temperature, leading to the shift of the resonance peak. The measured temperature sensitivity of the sensor is −562.4 pm/°C. In addition, the stability of the sensor is also measured. Due to high sensitivity, good stability, compact size and large temperature range, the proposed sensor shows promising potentials for temperature sensing in environment monitoring. • A novel high sensitive temperature sensor based on liquid filled fiber directional coupler is developed. • The liquid is filled into the air-hole of the eccentric hole-assistant dual-core fiber as the cladding of the suspended core and the heat-sensitive material. • Compared with other temperature sensors based on directional coupler with liquid core, the proposed sensor has a much larger temperature range. • The proposed temperature sensor has a good stability. The maximum fluctuation of the center wavelength of the resonance dip is less than ±0.1 nm. [ABSTRACT FROM AUTHOR]