Multichannel SPR (Surface Plasmon Resonance) optical fiber sensor based on bimetal and dual polarization

The invention provides a multichannel SPR (Surface Plasmon Resonance) optical fiber sensor based on bimetal and dual polarization. According to the sensor, the periphery of an optical fiber is polished to form four symmetrical channels, polished planes are coated with metal films (gold films or silver films) respectively, and TiO2 layers or Ta2O5 layers are added between the polished planes and the metal films. The polarization controller is used for controlling generation of dual-polarization (X-polarization or Y-polarization) light, the SPR effect generated between polarized light and different metals is used for detecting the refractive index of a medium to be detected, and therefore four-channel sensing detection is achieved. The invention has the advantages that the dual polarization can reduce the detection interference among the channels under different polarization, and the bimetal can reduce the detection interference among the channels under the same polarization, so that the low-interference multi-