Highly sensitive temperature sensing based on all-solid cladding dual-core photonic crystal fiber filled with the toluene and ethanol

An all-solid cladding dual-core photonic crystal fiber (DC-PCF) filled with toluene and ethanol is proposed for the temperature sensing. The all-solid cladding is formed by using the fluorine-doped silica glass instead of the air holes in the cladding region. By selectively filling the toluene and ethanol into the three air holes near the core region, the characteristic of the temperature sensing is numerically investigated. The simulation results show that the average sensitivity of the temperature sensing can achieve -11.64 and -7.41 nm/degrees C in the temperature ranges from 0 to 70 degrees C and -80 to 0 degrees C, respectively, when the length of the DC-PCF is as short as 1.6 mm. The maximum sensitivity in the considered temperature ranges can be up to -15 and -9 nm/degrees C, respectively. Moreover, the proposed temperature sensor is insensitive to the hydrostatic pressure.