抄録
A high-sensitivity refractive index (RI) sensor is proposed and designed, which is an in-line Mach-Zehnder interferometer (IMZI) with a photonic crystal fiber (PCF) and multilevel micro spindle structures fabricated by the arc-discharging and tapering method. To improve the sensitivity, a tapered multimode fiber (MMF) is inserted into the PCF. The performance of RI and temperature detection has been analyzed and discussed. The maximum RI sensitivity of -2958.875 nm/RIU is achieved by detecting the NaCl solution. In addition, the maximum temperature sensitivity is 6.4 pm/degree in the range of 25 degree - 65 degree, and the maximum measurement error changes caused by temperature is -0.0170 per mille/degree. It shows that the sensor is very sensitive to RI yet insensitive to temperature.