Effects of Tungsten Disulphide Coating on Tapered Microfiber for Relative Humidity Sensing Applications
Norazida Ali,
Saaidal Razalli Azzuhri,
Md Ashadi Md Johari,
Haroon Rashid,
Muhammad Imran Mustafa Abdul Khudus,
Mohd. Zulhakimi Ab. Razak,
Zhe Chen,
Norbahiah Misran,
Norhana Arsad
Affiliations
Norazida Ali
Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Malaysia
Saaidal Razalli Azzuhri
Department of Computer System and Technology, Faculty of Computer Science and IT, University of Malaya, Kuala Lumpur 50603, Malaysia
Md Ashadi Md Johari
Faculty of Engineering Technology, Universiti Teknikal Malaysia Melaka, Melaka 76100, Malaysia
Haroon Rashid
Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Malaysia
Muhammad Imran Mustafa Abdul Khudus
Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
Mohd. Zulhakimi Ab. Razak
Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Malaysia
Zhe Chen
Department of Optoelectronic Engineering, Jinan University, Road Huangpu, District Tianhe, Guangzhou 510632, China
Norbahiah Misran
Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Malaysia
Norhana Arsad
Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Malaysia
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.
