Author Affiliations
Abstract
Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China
A novel high sensitivity relative humidity (RH) sensor was proposed by using micro structure plastic optical fiber (POF) based on the surface plasmon resonance (SPR) effect and the evanescent wave (EW) loss. The micro structure was fabricated on the POF and coated with a gold layer and agarose, adopting the sputtering and dip-coating technique. These construction effects on the attenuation of power caused by the SPR effect and the EW loss were used to perform RH detections. The agarose’s different refractive indexes (RIs) caused fluctuations in the transmission power when the humidity increased. The demonstrated experimental results showed that the proposed sensor achieved a linear response from 20% RH to 80% RH with a high sensitivity of 0.595 μW/%. The proposed sensor had the advantages of fast response and recovery. Furthermore, the temperature dependence and the repeatability test of the sensor were also performed.
SPR evanescent wave loss agarose RH sensor Photonic Sensors
2021, 11(4): 392
Author Affiliations
Abstract
1 Department of Electrical Engineering, King Saud University, Riyadh 11421, Saudi Arabia
2 Department of Physics, University of Agriculture, Faisalabad 38040, Pakistan
Theoretical analysis of the electromagnetic field distribution in the focal region of a long metallic parabolic reflector that has its surface covered with a magnetized plasma layer is derived. The incident wave is considered to be with a general oblique incidence for both parallel and perpendicular polarizations. The electromagnetic field intensity expressions along the focal region are obtained accurately using Maslov’s method. The effects of plasma thickness on the reflected and transmitted field distributions are investigated. The effects of other physical parameters such as the angle of incidence and the plasma and cyclotron frequencies on the transmitted field-intensity distribution along the focal region are also studied. The results obtained by Maslov’s method and Kirchhoff’s approximation are found to be in a good agreement.
080.0080 Geometric optics Chinese Optics Letters
2015, 13(9): 090801
