Batch-producible Hybrid Fabry-Perot Fiber-Optic Sensors for Dual-parameters Measurement

In this paper, we proposed three kinds of the hybrid Fabry-Perot (FP) fiber-optic sensors based on Microelectro Mechanical System (MEMS) technology for dual-parameters measurement. MEMS technology can make sensors keep high consistency and have advantage in batch-production. These sensors, which are fabricated by silicon-glass anode bonding and silicon-silicon direct bonding techniques, have the same silicon cavities and the similar air cavities. We can achieve temperature sensing based on high thermo-optical coefficient of silicon cavity and achieve refractive index (RI) or pressure sensing by different structures of the air cavity. The experimental results demonstrated that the temperature sensitivity of these sensors is ~ 80 pm/°C. The sensor with groovesarray glass structure has RI sensitivity of 1535.8 nm/RIU in gas and 1043.36 nm/RIU in liquid, respectively. The sensors for pressure sensing which has holes-array glass structure has sensitivity of 47.89 pm/kPa, and which has holes-array silicon structure has sensitivity of 1003.79 pm/kPa. Furthermore, the latter has a lower temperature response in air cavity and can eliminate the influence of temperature on pressure cavity better.