High performance of SPR-based optical fiber pressure sensor: role of silicone rubber diaphragm

The high-sensitivity surface plasmon resonance-based optical fiber sensors for micro-pressure sensing is presented in this paper. The periodic micro-bending of two mechanical periodicities with length of 5 mm and 10 mm were used in the sensing system. The micro-pressure has been applied on the sensor for three different configurations: unclad sensor without gold (Au), unclad sensor with Au, and sensor with Au sandwiched between two layers of silicon rubber. The normalized output intensity for all configurations was calculated. The results show that the higher range of applied micro-pressure can be obtained for the configuration of optical fiber coated with Au sandwiched between two layers of silicon rubbers, with maximum sensitivity of 0.65 dB/kPs. The development model of the sensor could be a promising path for many different applications.