We demonstrate experimentally, the generation of an intense broadband comb-like spectrum spontaneously built up through stimulated Raman scattering in a low-pressure CO-filled hollow-core photonic crystal fiber pumped by a single infrared pump.
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http://dx.doi.org/10.1364/OL.44.005318 | DOI Listing |
Nanophotonics
January 2025
Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Kasprzaka 44/52, Poland.
A combination of femtosecond stimulated Raman scattering and surface-enhanced Raman scattering, termed surface-enhanced stimulated Raman scattering (SE-FSRS), was proposed to leverage both temporal precision and sensitivity for advanced molecular dynamics analysis. During the initial successful implementations of this approach, unexpected spectral distortions were observed, and several potential explanations were proposed. Further progress in this novel technique and its broader implementation requires a profound understanding of the factors influencing the shape of the registered spectra and the underlying mechanisms.
View Article and Find Full Text PDFAnal Chem
January 2025
State Key Laboratory of Surface Physics and Department of Physics, Academy for Engineering and Technology, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Key Laboratory of Metasurfaces for Light Manipulation, Fudan University, Shanghai 200433, China.
Numerous chemical reactions and most life processes occur in aqueous solutions, where the physical diffusion of small molecules plays a vital role, including solvent water molecules, solute biomolecules, and ions. Conventional methods of measuring diffusion coefficients are often limited by technical complexity, large sample consumption, or significant time cost. Here, we present an optical imaging method to study molecular diffusion by combining stimulated Raman scattering (SRS) microscopy with microfluidics: a "Y"-shaped microfluidic channel forming two laminar flows with a stable concentration gradient across the interface.
View Article and Find Full Text PDFFood Chem
January 2025
College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, Hubei, China. Electronic address:
Spirulina platensis (SP) provides humans with proteins and natural pigments. The effects of micro/nanoplastics (MNPs) on SP are of great interest. We focused on the effects of high concentrations (100-300 mg/L) of polystyrene MNPs on SP for 50 days.
View Article and Find Full Text PDFNat Methods
January 2025
Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA.
Super-resolution imaging of cell metabolism is hindered by the incompatibility of small metabolites with fluorescent dyes and the limited resolution of imaging mass spectrometry. We present ultrasensitive reweighted visible stimulated Raman scattering (URV-SRS), a label-free vibrational imaging technique for multiplexed nanoscopy of intracellular metabolites. We developed a visible SRS microscope with extensive pulse chirping to improve the detection limit to ~4,000 molecules and introduced a self-supervised multi-agent denoiser to suppress non-independent noise in SRS by over 7.
View Article and Find Full Text PDFIn this study, we investigated in detail the regulation mechanism of electron transfer under laser-induced breakdown (LIB) on weak O-D stimulated Raman scattering (SRS) in DMSO-DO solutions. Significantly, the Raman activity of O-D vibrations was greatly enhanced by two orders of magnitude due to electron transfer in DMSO molecules. Density functional theory (DFT) calculations showed that the O-D Raman activity was significantly enhanced in the DMSO-DO dimer compared to the DO dimer.
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