experimental and theoretical analysis of connector offset optical fiber refractive index sensor

In this paper, a high sensitive connector offset optical fiber sensor is employed to detect the refractive index of liquid. the configuration chosen for this experiment is formed by lateral core offset fusion splicing of no-core fiber (ncf) between the single mode fibers (smf) and cladding modes are excited by misalignment. the sensing principle for refractive index detection is based on mach-zehnder interferometer (mzi) principle and the experiment is carried out by immersion of device in nacl solutions of different refractive indices. such refractive index sensor exhibits high sensitivity 197.33 nm/riu for the surrounding refractive index variation from 1.333 to 1.380, and the result shows the excellent agreement with theoretical analysis. compared to other sensors, the proposed device has the potential to provide high sensitivity, ease of fabrication, low cost, compact size, and linear response. thus, it can be used in many applications such as bio-sensors, chemical sensor, temperature sensor, and pressure sensor.