ساخت حسگر رطوبت با استفاده از سطح مقطع فيبر نوري

Among the structures of fiber optic sensors, the fiber tip structure provides discreet access to remote, confined environments, and those with extreme temperature, pressure, and electromagnetic interference. The sensitivity of these types of sensors can be enhanced either by designing appropriate structures at the fiber tip or by coating the tip with nanoparticles or nanostructures. In this study, a fiber optic sensor was developed for humidity measurement using the fiberʹs cross-section. By fabricating a single-mode adiabatic microfiber structure at the fiber tip and coating it with zinc oxide nanorods, we successfully created a fiber optic humidity sensor with relatively high sensitivity utilizing the fiber’s cross-sectional area. This sensor offers easy fabrication, reduced cost, and due to its larg diameter (20 micrometers), advantages in terms of stability and ease of handling. The sensor’s sensitivity was eva‎luated by measuring the intensity variation in response to environmental humidity using two methods: reflected light collection and transmitted light collection. In the first method, the transmitted light was collected by a detector and displayed using an oscilloscope. The sensor demonstrated a sensitivity 2.1228⁄(%RH), with intensity variations following a linear trend and a correlation coefficient of 97%. Additionally, the sensor exhibited a response time of 27 seconds and a recovery time of 25 seconds for humidity changes from 32% to 85%. In the sensor based on the fiber’s cross-sectional area, the reflected light was collected using a BraggMETER spectrometer and displayed on a computer. This sensor showed a sensitivity 1.2822⁄(%RH) for humidity changes, with intensity variations following a linear trend and a correlation coefficient of 90%.

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