  In this work, we proposed a high resolution D-shaped photonic crystal fiber
(PCF) surface plasmon resonance (SPR) sensor based on gold grating. Gold
grating is introduced to modulate the resonance wavelength and enhance the
refractive index (RI) sensitivity. Structure parameters of PCF and gold grating
are analyzed by finite element method (FEM) for optimizing the SPR sensor. The
simulation results indicate that air hole pitch, air hole diameter and gold
thickness and grating constant have little influence on the sensitivity of
refractive index, which reduces the requirement of precise processing. For
improving the resolution of RI sensing, two-feature (2F) interrogation method
which combines wavelength interrogation and amplitude interrogation is used and
the maximum theoretical resolution of SPR sensor reaches to 5.98*10-6 RIU in
range of 1.36-1.38 and the wavelength sensitivity reaches to 3340nm/RIU. The
proposed SPR sensor shows potential applications on developing a
high-sensitivity, real time and fast-response SPR-RI sensor.
