Highly sensitive selectively coated D-shape photonic crystal fibers for surface plasmon resonance sensing

We propose a design for a high sensitivity plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) and analyze the sensor using finite element software (FEM). By introducing a D-shape hole instead of a circular hole in the first ring of the photonic crystal fiber, which increases the coupling effect and proficient infiltration of the sensing, resulting in enhance the performance of the sensor due to the flat structure of the D-shape hole and the homogeneous metal coating facility. We study the influence of the parameters of the D-shape hole on the sensing performance and analyze the sensor performance based on the wavelength and amplitude sensitivity. The results show that the proposed sensor is capable of detecting analyte refractive index ranging from 1.30 to 1.42, and the maximum sensitivities of 14,600 nm/RIU and 1475 RIU^?1 can be achieved in this sensing range, respectively. The largest sensor resolutions for wavelength and amplitude sensing are $6.84\times {10}^{?6}$ and $6.78\times {10}^{?6}\text{ RIU}$, and the maximum figure of merits (FOM) of the proposed sensor being 618.