A wavelength step-swept light source (WSSL) using a recirculating frequency shifter loop (RFSL) based on a single-side-band (SSB) modulator is proposed, in order to achieve a linear and fast wavelength-sweeping. The swept step can be tuned from 1.2 pm to 128 pm by adjusting a precise and stable radio frequency (RF) signal that is applied to the SSB modulator. The swept rate can be tuned up to 99 kHz in a range of over 5.12 nm. Wavelength-to-time mapping is used to measure static strain-induced or temperature-induced shifting of the reflected central wavelength of a fiber Bragg grating (FBG). Because of the high linearity of the light source, the interrogation linearity of the strain and the temperature are as high as 0.99944 and 0.99946, respectively. When a dynamic periodic strain applied to FBG sensor, the dynamic performance of the FBG sensor is successfully recorded in the time domain and its power spectral density of a fast Fourier transform (FFT) is calculated. The signal-to-noise ratio (SNR) of the power spectral density is over 40 dB for a 100 Hz dynamic strain and the calculated sensitivity is 0.048 με/Hz. A sharp change in the strain frequency from 100 Hz to 500 Hz is captured in real time.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6387006 | PMC |
| http://dx.doi.org/10.3390/s19030593 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared.
J Vis Exp
January 2025
Department of Biomedical Engineering, Washington University in St. Louis; Department of Obstetrics & Gynecology, Washington University in St. Louis;
For noninvasive light-based physiological monitoring, optimal wavelengths of individual tissue components can be identified using absorption spectroscopy. However, because of the lack of sensitivity of hardware at longer wavelengths, absorption spectroscopy has typically been applied for wavelengths in the visible (VIS) and near-infrared (NIR) range from 400 to 1,000 nm. Hardware advancements in the short-wave infrared (SWIR) range have enabled investigators to explore wavelengths in the ~1,000 nm to 3,000 nm range in which fall characteristic absorption peaks for lipid, protein, and water.
View Article and Find Full Text PDFBioactivities of secondary metabolites of two actinomycetes Streptomyces parvulus GloL3, and Streptomyces lienomycini SK5, endophytes of two Indian medicinal herbs- Globba marantina L. and Selaginella kraussiana (Kunze) A. Braun.
Braz J Microbiol
January 2025
Microbiology and Microbial Biotechnology Laboratory, Department of Botany and Forestry, Vidyasagar University, 721102, Midnapore, West Bengal, India.
Endophytic actinomycetes are potential sources of novel pharmaceutically active metabolites, significantly advancing natural product research. In the present investigation, secondary metabolites from two endophytic actinomycetes, Streptomyces parvulus GloL3, and Streptomyces lienomycini SK5, isolated from medicinal plant taxa, Globba marantina, and Selaginella kraussiana, exhibited broad-spectrum bioactivity. Ethyl Acetate (EA) extract of SK5 showed antimicrobial activity against nine human pathogens, including Methicillin-resistant Staphylococcus aureus (MRSA), Candida tropicalis, and C.
View Article and Find Full Text PDFA multi-scale cognitive interaction model of instrument operations at the Linac Coherent Light Source.
Rev Sci Instrum
January 2025
Bennu Climate, Inc. and Symbolic Systems Program, Stanford University, Stanford, California 94305, USA.
The Linac Coherent Light Source (LCLS) is the world's first x-ray free electron laser. It is a scientific user facility operated by the SLAC National Accelerator Laboratory, at Stanford, for the U.S.
View Article and Find Full Text PDFNoble-Metal-Free ZnII-Anchored Pyrene-Based Covalent Organic Framework (COF) for Photocatalytic Fixation of CO2 from Dilute Gas into Bioactive 2-Oxazolidinones.
ChemSusChem
January 2025
Indian Institute of Technology Ropar, Chemistry, Nangal Road, 140001, Rupnagar, INDIA.
Photocatalytic conversion of CO2 into value-added chemicals offers a propitious alternative to traditional thermal methods, contributing to environmental remediation and energy sustainability. In this respect, covalent organic frameworks (COFs), are crystalline porous materials showcasing remarkable efficacy in CO2 fixation facilitated by visible light owing to their excellent photochemical properties. Herein, we employed Lewis acidic Zn(II) anchored pyrene-based COF (Zn(II)@Pybp-COF) to facilitate the photocatalytic CO2 utilization and transformation to 2-oxazolidinones.
View Article and Find Full Text PDFOpen-source implementation of polarisation-resolved single-shot differential phase contrast microscopy () on a modular -based microscope.
HardwareX
March 2025
LIGHT Community, Physics Department, Imperial College London SW7 2AZ, UK.
We recently demonstrated polarisation differential phase contrast microscopy () as a robust, low-cost single-shot implementation of (semi)quantitative phase imaging based on differential phase microscopy. utilises a polarisation-sensitive camera to simultaneously acquire four obliquely transilluminated images from which phase images mapping spatial variation of optical path difference can be calculated. microscopy can be implemented on existing or bespoke microscopes and can utilise radiation at a wide range of visible to near infrared wavelengths and so is straightforward to integrate with fluorescence microscopy.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!