In this study, we present a new concept for the simple visual detection of nano-scale objects in solutions. To achieve this goal, we developed chromogen-free interference-based sensors that provided a color visible reaction directly after the interaction of the analyte with the substrate. The effect is based on the strong optical interference occurring at the interface between the inkjet printed sol-gel titania film (a layer with high refractive index) and the adsorbed nano-sized objects (layer with low refractive index), which can be detected even with the naked eye. Herein, we have developed a synthetic strategy for the inkjet printing of interference sensors with controllable color change through thickness adjustment.
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http://dx.doi.org/10.1039/c9nr00616h | DOI Listing |
Sensors (Basel)
December 2024
Key Laboratory of Electromagnetic Wave Information Technology and Metrology of Zhejiang Province, College of Information Engineering, China Jiliang University, Hangzhou 310018, China.
This paper presents research on the security performance of a multi-user interference-based mixed RF/FSO system based on SWIPT untrusted relay. In this work, the RF and FSO channels experience Nakagami-m fading distribution and Málaga (M) turbulence, respectively. Multiple users transmit messages to the destination with the help of multiple cooperating relays, one of which may become an untrusted relay as an insider attacker.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Key Laboratory of Spectral Imaging Technology, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China. Electronic address:
Traditional ultraviolet-visible spectroscopic quantitative analytical methods face challenges in simultaneous and long-term accurate measurement of chemical oxygen demand (COD) and nitrate due to spectral overlap and the interference from stochastic background caused by turbidity and chromaticity in water. Addressing these limitations, a compact dual optical path spectrum detection sensor is introduced, and a novel ultraviolet-visible spectroscopic quantitative analysis model based on physics-informed multi-task learning (PI-MTL) is designed. Incorporating a physics-informed block, the PI-MTL model integrates pre-existing physical knowledge for enhanced feature extraction specific to each task.
View Article and Find Full Text PDFWe propose a multimode interference-based optical fiber NHTSN sensor with a helical taper for simultaneous measurement of micro torsion and temperature. The sensor consists of single mode fiber (SMF), no-core fiber (NCF), and seven-core fiber (SCF). A helical taper is fabricated in the SCF using a flame heater, forming the SMF-NCF-Helical Taper SCF-NCF-SMF (NHTSN) structure.
View Article and Find Full Text PDFWe propose and demonstrate a new, to the best of our knowledge, microwave interference-based scheme with high sensitivity and tunable measurement range, which is realized by a Mach-Zehnder interferometer (MZI). A chirped fiber Bragg grating and single-mode fiber serve as the two unbalanced arms of the RF interferometer. The induced differential chromatic dispersion transfers the wavelength shift of the fiber Bragg gratings to the change of the RF phase difference between the two interferometric carriers, which ultimately leads to the variation of the RF signal intensity.
View Article and Find Full Text PDFSensors (Basel)
September 2023
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China.
This paper presents a real-time underwater wireless optical communication (UWOC) system. The transmitter of our UWOC system is equipped with four blue LEDs, and we have implemented pre-emphasis technology to extend the modulation bandwidth of these LEDs. At the receiver end, a 3 mm diameter APD is utilized.
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