Effects of Tungsten Disulphide Coating on Tapered Microfiber for Relative Humidity Sensing Applications

Abstract

Tungsten disulphide (WS2) is a two-dimensional transition-metal dichalcogenide material that can be used to improve the sensitivity of a variety of sensing applications. This study investigated the effect of WS2 coating on tapered region microfiber (MF) for relative humidity (RH) sensing applications. The flame brushing technique was used to taper the standard single-mode fiber (SMF) into three different waist diameter sizes of MF 2, 5, and 10 µm, respectively. The MFs were then coated with WS2 via a facile deposition method called the drop-casting technique. Since the MF had a strong evanescent field that allowed fast near-field interaction between the guided light and the environment, depositing WS2 onto the tapered region produced high humidity sensor sensitivity. The experiments were repeated three times to measure the average transmitted power, presenting repeatability and sensing stability. Each MF sample size was tested with varying humidity levels. Furthermore, the coated and non-coated MF performances were compared in the RH range of 45–90% RH at room temperature. It was found that the WS2 coating on 2 µm MF had a high sensitivity of 0.0861 dB/% RH with linearity over 99%. Thus, MF coated with WS2 encourages enhancement in the evanescent field effect in optical fiber humidity sensor applications.

Effect of Coated Tungsten Disulfide (WS2) on Tapered Optical Fibre for Urea Detection

“…This material has emerged as a new class of fascinating 2-dimensional transition metal dichalcogenides due to its unique properties, which include direct band gaps, superior flexibility, moderate carrier mobility, biocompatibility, and layerdependent electrical and optical properties. It is a promising candidate for future applications in electronic devices, particularly in sensing technology [26][27][28]. This study hypothesizes that the amount of tungsten disulfide (WS2) coating an optical sensor has may affect the sensitivity to different urea concentrations.…”

Highly Sensitive Photothermal Fiber Sensor Based on MXene Device and Vernier Effect

“…Optical fiber sensors with the interferometer structure often use a tapered-fiber-based sensing device. Tapered fiber has the advantages of low loss, a high evanescent field, and easy integration, and is a breakthrough in the fabrication of miniaturized photonic devices, including phase fiber sensors [ 2 ]. Tapered-fiber-based photonic device microfiber knot resonators ( MKRs , tapered fiber knotting) are one of the research hotspots in the field of phase fiber sensors.…”