Hygroscopic polymer microcavity fiber Fizeau interferometer incorporating a fiber Bragg grating for simultaneously sensing humidity and temperature

Enhancing Temperature Sensitivity of the Fabry–Perot Interferometer Sensor with Optimization of the Coating Thickness of Polystyrene

“…The two reflected light intensities backed into the SMF are denoted as r 1 and r 2 respectively. Thus performance of the cavity can be approximated by a two beam interferometric model, and the output intensity of r can be expressed as [33,35].…”

“…The two reflection surfaces are on the sensing head, i.e., fiber-polymer and polymer−air, where R 1 and R 2 are the Fresnel reflection coefficients for two surfaces, respectively. The reflection of light happened on the both surfaces is the Fresnel reflection; consequently, R 1 and R 2 can be determined as follows [32][33][34].…”

Relative Humidity Fiber Sensor Based on Multimode Interferometer Coated with Agarose-Gel

“…Different fiber sensing structures have been combined with polymer coatings. For instance, the use of fiber Bragg gratings [23], bended fibers [24], side-polished fibers [25,26], photonic crystal fibers [20,27], tapered fibers [13,15,16], Fabry-Perot cavities [28], Sagnac interferometers [29], hollow core fibers [15], and single-mode hetero-core fibers [14,30] have been proposed to detect environmental RH variations.…”

“…This sensor has a great potential in real time RH monitoring and can be of interest for applications where a control of high levels of relative humidity is required.Coatings 2018, 8, 453 2 of 9 and desorb water, and also to restore a fast equilibrium with atmospheric humidity. Besides that, it is extremely stable, not soluble in water and can be easily handled for device manufacture [23,31].In this work, a multimode interferometer based on a coreless fiber coated with agarose gel is proposed for the detection of RH. The sensor is easy to produce, presents good resolution, particularly for environments with values of RH higher than 60.0%RH.…”

“…Coatings 2018, 8, 453 2 of 9 and desorb water, and also to restore a fast equilibrium with atmospheric humidity. Besides that, it is extremely stable, not soluble in water and can be easily handled for device manufacture [23,31].…”