An Optical Sensor Designed From Cascaded Anti-Resonant Reflection Waveguide and Fiber Ring-Shaped Structure for Simultaneous Measurement of Refractive Index and Temperature

A novel optical fiber sensor based on cascade anti-resonant reflection waveguide (ARRW) and fiber ring-shaped structure (FRSS) is proposed and experimentally demonstrated for simultaneous measurement of refractive index (RI) and temperature. The sensor is very simply fabricated by splicing ARRW and FRSS based on Mach-Zehnder interference (MZI). The FRSS interference dip is sensitive to external RI and temperature changes, whereas the ARRW structure's loss dip is only sensitive to external temperature. As a result, this sensor can be used to measure both RI and temperature simultaneously. The sensor's maximum RI sensitivity is 108.61 nm/RIU and its maximum temperature sensitivity is 19 pm/ °C in the experiment. This sensor is a good choice when it is necessary to measure RI and temperature at the same time due to its compact size, high sensitivity, low cost, and good stability.