Analysis of Double Peak Detection in a D-Shaped Photonic Crystal Fiber Plasmonic Sensor

We present a novel D-shaped photonic crystal fiber sensor with double loss peaks based on surface plasmon resonance. The proposed sensor has a lot of better characteristics for refractive index detection compared with single-peak sensor. It is worth noting that the trough of the loss spectrum keeps unchanged as the analyte refractive index increases, which indicates that this sensor is extremely stable. In addition, numerical simulation shows that the average wavelength sensitivity can reach 29,000 nm/RIU and the maximum resolution is as high as 3.45 x 10(-5) RIU. Furthermore, the coupling theory between fundamental mode and the surface plasmon polarization (SPP) mode is investigated in this paper. It is found that there is obvious competition between the resonant modes. This study has enlightening significance for us to understand the generation mechanism of polarization-entangled quantum photo source.

Automated summary

The novel D-shaped photonic crystal fiber sensor with double loss peaks based on surface plasmon resonance shows better characteristics for refractive index detection than single-peak sensor. The sensor remains stable as the analyte refractive index increases, with numerical simulation demonstrating high average wavelength sensitivity and resolution. Additionally, the coupling theory between fundamental mode and SPP mode reveals competition between resonant modes, providing insight into the generation mechanism of polarization-entangled quantum photo source.