Tamm Plasmon Polariton Based Hollow Fiber Refractive Index Sensor With One-Dimensional Photonic Crystal/Metal Structure

A high performance hollow fiber refractive index (RI) sensor utilizing Tamm plasmon polariton (TPP) is proposed. The structure of the sensor is a HF with the one-dimensional photonic crystal (1DPC)/metal multi-films coated on the inner surface of supporting tube. Theoretical analysis based on a ray transmission model is carried out to evaluate the performance of the designed sensor. Because the lights transmitted in the HF have much larger incident angles than those in the prism based sensors, the center wavelength of the 1DPC should shift to longer wavelength. The origin of multiple resonance dips in the transmission spectrum is investigated by calculating the dispersion curve of TPP and the electric field distribution in the 1DPC/metal structure. The performance and the variation of the RI detection range of the sensor with different bilayer period is also analyzed theoretically. The optimal bilayer period of the sensor for achieving the highest figure of merit (FOM) at different sensed RI is obtained. Compared to the conventional HF surface plasmon resonance sensors which can only detect sensed medium with RI higher than that of the supporting tube material, the RI detection range of the proposed sensor is largely extended to 1.33–1.60 while the FOM is enhanced several times.