highly sensitive refractive index sensor based on four-hole grapefruit microstructured fiber with surface plasmon resonance

A highly sensitive refractive index (ri) sensor based on four-hole grapefruit fiber with surface plasmon resonance (spr) has been proposed and theoretically investigated. by coating gold film on the wall of large air holes in grapefruit fiber, the ri sensitivity of the proposed sensor could be effectively improved because of spr effect. it can be found that the thickness of gold film plays an important role for spr by numerically analyzing the transmission spectra characteristics of the sensor. the simulation results show that the sensitivity of the analyte which has a high ri is higher than that of the low in ri range of 1.33 to 1.43, and an extremely high ri sensitivity of 19,000 nm/riu can be achieved at 1.43. due to the excellent performances in high ri sensing range, the proposed sensor has the potential to be used for the measurement of organic chemicals that high-precision ri measurement is required.