Microfiber Assisted Highly Birefringent PCF-Based Interferometric Sensors

We propose a highly sensitive interferometric sensor based on a tapered fiber concatenated with a highly birefringent (HiBi) photonic crystal fiber (PCF) for the detection of physical as well as chemical parameters. The splicing of single mode fiber (SMF) and HiBi PCF is achieved without any offset. The tapered section is employed for curvature and temperature sensing while the HiBi PCF is used for refractive index sensing. Experimental results show that the proposed Mach–Zehnder interferometer has a curvature sensitivity of 14.77 nm/m −1 with a resolution of $6.77 \times 10^{\mathrm {\mathbf {-4}}}\,\,\text{m}^{\mathrm {\mathbf {-1}}}$ . Furthermore, the refractive index (RI) sensitivity is found to be 257 nm/RIU along with a resolution of $3\times 10^{\mathrm {\mathbf {-5}}}$ RIU, which is comparable to commercial refractometer. The proposed setup shows a temperature sensitivity of 311 pm/°C. The curvature, RI, and temperature sensitivity are significantly higher with linear response.