A Hybrid Multimode Interference Structure Based Refractive Index and Temperature Fiber Sensor
A novel all fiber sensor based on cascaded singlemode no core singlemode (SNS) and siglemode multimode singlemode (SMS) fiber structure is proposed and investigated. Simulation results show that for the given fibers, by appropriately choosing the lengths of no core fiber and multimode fiber, the transmission spectrum will exhibit two distinguishable dips corresponding to SNS and SMS, respectively. The simultaneous measurement of liquids' refractive index (RI) and temperature can be realized by monitoring the two dips' central wavelength shifts. According to the simulations, a corresponding sensor is fabricated and tested. The experimental results demonstrate the feasibility of the sensor and show that the sensor has the RI and temperature sensitivities of 113.66 nm/RIU and 9.2 pm/degC, respectively.
IEEE Sensors Journal