High Sensitivity Surface Plasmon Resonance Sensor Based on ITO-Coated Photonic Crystal Fiber with Simple Structure

The design flexibility of photonic crystal fiber (PCF) is convenient for sensor design. In this paper, we propose a high sensitivity surface plasmon resonance (SPR) sensor based on indium tin oxide (ITO)-coated PCF with simple structure. A structure consisting of four square air holes is used for the sensing of bio-analytes.To supports the SPR, we use a novel conductor material for ITO and a continuous metal film to help improve the sensing performance. According to numerical results, the maximum wavelength sensitivity of the sensor can reach 28500 nm/RIU. It has high wavelength resolution of 3.5×10 − 6 RIU and the refractive index detection range of the sensor is 1.33–1.40. Besides, the sensor has a highly linear sensing performance. Considering the simple structure and competitive sensing performance,the sensor can detect the refractive index of liquid in a wide range and accurately detect the refractive index of liquid in a small range such as plasma, hemoglobin,etc.