Traditionally, Rayleigh scattering is thought to only impact fiber sensing system performance when the leading fiber is over 10 km long. However, this report illustrates theoretically and experimentally that Rayleigh scattering cannot be ignored in fiber optic interferometric sensor (FOIS) even with several hundred-meter common leading fiber because of the interaction of Rayleigh backward scattering (RBS) and returning interference signal. Herein, a conceptual framework is developed to elucidate the interaction between RBS and FOIS interference, revealing that, beyond laser monochromacity, the self-correction characteristic of laser pulses also influences coherent superposition. Building upon this novel insight, a phase modulation method based on pseudorandom noise (PRN) code is first proposed to address coherent RBS stacking on returning FOIS interferences while preserving high laser monochromacity. By modulating the interrogation pulses, a 21.3 dB suppression of background phase noise is achieved in FOIS with 3.3 km leading fiber. This study offers a holistic understanding of Rayleigh scattering in the leading fiber, encompassing experimental observations, theoretical modeling, physics analysis, and its resolution, thereby contributing to advancements in underwater sensing to broaden the understanding of the underwater environment.
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http://dx.doi.org/10.1002/advs.202411967 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin 541004, China; Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin 541004, China. Electronic address:
A new magnetic-liquid crystal nanosurface molecularly imprinted polymer (5CB-FeO@MIP) resonance Rayleigh scattering temperature sensor was prepared, using liquid crystal 4'-cyano-4'-pentylbiphenyl as the temperature sensing element, nano-FeO as the substrate, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinking agent. It was characterized by molecular spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy. The thermosensitive effect of 11 liquid crystals, that is, the relationship between RRS and temperature, was studied.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Faculdade de Ciências, Universidade Estadual Paulista (UNESP), Bauru 17033-360, SP, Brazil.
This study evaluates how the polarity of the medium affects the binding efficiency of hydrophobic ligands with human serum albumin (HSA). The polarity of the aqueous medium was changed by adding 1,4-dioxane in concentrations of 0%, 10%, and 20% /, resulting in solvent mixtures with decreasing dielectric constants (ε = 80, 72, and 63). The addition of 1,4-dioxane did not affect the integrity of the protein, as confirmed by Far-UV-CD, Rayleigh scattering, and time-resolved fluorescence experiments.
View Article and Find Full Text PDFACS Polym Au
December 2024
Department of Chemistry and Biochemistry, Seton Hall University, South Orange, New Jersey 07079, United States.
Unusual photophysical and scattering behavior is described for hyperbranched poly(phenylene sulfide) materials. These materials show interactions between the π systems of the aromatic monomer units in both ground and excited states, resulting in broad ranges for absorption and emission of light. The materials also display unusual scattering behavior; this is attributed to enhanced scattering by delocalized excited states resulting from the monomer unit interactions.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Univ. Bordeaux, CNRS, Bordeaux INP, Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France.
The effect of conformational dynamics and solvent interactions on the second-order nonlinear optical (NLO) responses of the open and closed forms of a donor-acceptor Stenhouse adduct (DASA) are investigated by a mixed quantum/classical computational approach, which couples molecular dynamics (MD) simulations and time-dependent density functional theory (TD-DFT) calculations. The latter are further combined with various solvation schemes, including polarizable continuum models, hybrid QM/MM approaches using either non polarizable or polarizable electrostatic embedding, and QM/QM' schemes with explicit treatment of a few molecules of the first solvation shell. The performances of the different solvation models are discussed in the context of comparisons with experimental data obtained from hyper-Rayleigh scattering measurements.
View Article and Find Full Text PDFEcol Evol
December 2024
Conservation Ecology Research Unit, Department of Zoology and Entomology University of Pretoria Pretoria South Africa.
Light is a fundamental attribute and key abiotic driver in forest ecosystems. Although the ecological effects of light itself is well studied, capturing the complex parameters that constitute the whole light environment remain an intricate research endeavor. Here, we apply the newly introduced environmental light field (ELF) technique in Kibale National Park, Uganda.
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