tunable surface plasmon resonance sensor based on photonic crystal fiber filled with gold nanoshells

We present a photonic crystal fiber (pcf)-based surface plasmon resonance (spr) sensor, whose operating wavelength range is tunable. gold nanoshells, consisting of silica cores coated with thin gold shells, are designed to be the functional material of the sensor because of their attractive optical properties. it is demonstrated that the resonant wavelength of the sensor can be precisely tuned in a broad range, 660 nm to 3.1 μm, across the visible and near-infrared regions of the spectrum by varying the diameter of the core and the thickness of the shell. furthermore, the effects of structural parameters of the sensor on the sensing properties are systematically analyzed and discussed based on the numerical simulations. it is observed that a high spectral sensitivity of 4111.4 nm/riu with the resolution of 2.45 × 10−5 riu can be achieved in the sensing range of 1.33–1.38. these features make the sensor of great importance for a wide range of applications, especially in biosensing.