Photonics Crystal Fiber for Salinity Sensing Applications with A Large Negative Dispersion.

In this study, we propose a novel approach to enhance the sensitivity of salinity measurement using photonic crystal fiber. Our method involves filling the first ring of holes in the fiber with seawater, which serves as the analyte, and embedding it in a single-material silica substrate. This design allows for precise tuning of sensitivity to even minimal changes in salinity concentration. Through numerical simulations, we explore the influence of different geometrical parameters on the photonic crystal fiber's (PCF) characteristics. We calculate the sensitivity for two wavelengths, 1.3µm and 1.55µm, and achieve a highest salinity sensitivity of 0.017966 ps/(nm·km)/PSU and 0.021818 ps/(nm·km)/PSU, respectively. Our proposed sensor not only demonstrates excellent performance in salinity sensing but also holds promise for applications in the field of communication, thanks to its satisfactory and impressive sensing capabilities. [ABSTRACT FROM AUTHOR]