Highly Sensitive Side-Polished Birefringent PCF-Based SPR Sensor in near IR

Abstract

We propose a highly sensitive side-polished birefringent photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR). The polished surface of the proposed structure is coated with indium tin oxide (ITO) to excite plasmon and the analytes can be placed on the flat surface easily instead of filling the voids. The birefringent nature of the structure helps in coupling more fields to the ITO-dielectric interface. With the optimum thickness of 110 nm of ITO, the structure shows a maximum wavelength sensitivity of 17000 nm/RIU with a resolution of 5.8 × 10−6 RIU. Further this also showed an amplitude sensitivity of 74 RIU−1 along with a resolution of 1.35 × 10−5 RIU. Moreover, the effect of bending on this low loss structure is also analyzed.