A reflector-less refractive index fiber sensor, exploiting the high-scattering of a MgO nanoparticle (NP) fiber, is proposed. The sensor is obtained by etching the fiber to expose the core to the surrounding analyte, and the backscattering signal is read by an Optical Backscatter Reflectometer (OBR). This approach permits distributed sensing, offered by OBR detection, and permits spatial-multiplexing of parallel sensors, thanks to the scattering-level multiplexing (SLMux) of the NP-doped fiber. Simultaneous physical properties detection is also possible. Experiments, performed to detect refractive index and temperature, showed a sensitivity of roughly 0.6 nm/RIU, with a simultaneous measurement of 100°C of temperature.
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