Simulation of Bare Trench Silica Fiber Sensor for Humidity Sensing

Trench coreless silica fiber or known as (TCSF) is a type of coreless silica fiber (CSF) which is considerably famous optical fiber for its application as humidity sensitive materials. Nevertheless, increase in cost and introducing substantial cross sensitivity of temperature due to the limitations of intrinsic and nature of foreign materials or substances complicate during the fabrication process of TCSF or CSF as based humidity sensors. Apropos, this paper introduces a simulation of a bare TCSF which the width and depth of 50μm design for humidity sensing rather than simulating a CSF to know how sensitive TCSF is. Hence, evaluation of the sensor's performance by simulating changes in the analyte refractive index, ranging from 1.000 RIU (representing air) to 1.350 RIU (representing water), to assess its humidity-sensing capabilities. These, results indicate that the bare or uncoated TCSF design successfully detects humidity (1.00 to 1.35 RI), achieving a sensitivity of 593.7 × 10⁻⁹ RIU per unit of RI change and demonstrating strong linearity with an $\mathrm{R}^{2}$ value of 0.9299. Therefore, the results laid the groundwork for future optimizations of the uncoated TCSF humidity sensor's performance through suggested possible design modifications.