Highly efficient symmetrical dual-channel D-type photonic crystal fiber surface plasmon resonance sensor

In order to improve the efficiency and accuracy of analytes’ refractive index (RI) detection, a symmetrical dual-channel D-type photonic crystal fiber surface plasmon resonance sensor is proposed. Dependent on the characteristics of dual-channel structure, the analytes are filled in both sides of the channel at the same time. The full vector finite-element method is adopted for numerical analysis to optimize the structural parameters of the sensor. The results show that when the silver (Ag) and titanium dioxide ( T i O 2 ) layer thickness are 50 nm and 10 nm, respectively, the Ag- T i O 2 microgratings number in one side channel is 50, and the spacing is 30 nm. The maximum wavelength sensitivity is 14,000 nm/RIU for both channels for the RI changing from 1.33 to 1.40. It is proved that it can detect analytes’ RI in two channels at the same time. And the use scene of the sensor is explained in detail. As a result, it can not only reduce the time cost of cleaning the detection channel and checking the symmetry of two channels, but also be used to judge whether the RI of analytes in two channels is the same, which improves the detection efficiency and accuracy in biology and chemistry.