Dual-channel surface plasmon sensor based on photonic crystal fiber for low refractive index detection

In this paper, a surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) which can be filled with multiple analytes is proposed. The sensor has two elliptical groove microchannels. By changing the depth of the groove, the distance between the analyte to be measured and the sensor core can be reduced, thereby enhancing the energy coupling between the core mode and the plasma mode. The sensor can achieve both single-channel operation and dual-channel simultaneous measurement, which can effectively improve the detection efficiency. When the two channels work simultaneously, the maximum wavelength sensitivity of 1900 nm/RIU and 18,000 nm/RIU can be achieved by channel 1 and channel 2, respectively. The refractive index detection range of the sensor is 1.17 to 1.30. As far as we know, this is the first PCF-SPR sensor that dual channels are introduced into low refractive index detection.