We report the construction and characterization of a coherent Raman tabletop system utilizing a novel astigmatic optical focusing geometry, a broadband nanosecond optical parametric oscillator and volumetric Bragg filters assisting 3CBCRS measuring system for the first time. In order to illustrate the versatility of the measurements and reveal the molecular information obtainable, two well-characterized chemicals were selected. Polarization sensitive epi-detected 3CBCRS spectra of liquid CCl and calcite crystal were recorded and analyzed. An unexpected polarization dependence of the signals of the lowest frequency modes of CCl was observed. The 1122 third order susceptibility component was phase flipped. The non-resonant susceptibility normalized 1122 component was found to be larger than the 1111 component for the lowest vibrational modes. This anomalous comportment was attributable to the anisotropy Raman tensor invariant in the third order nonlinear susceptibility tensor.
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http://dx.doi.org/10.1016/j.saa.2018.03.033 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
DICP: Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, CHINA.
Broad-temperature optical thermometry necessitates materials with exceptional sensitivity and stability across varied thermal conditions, presenting challenges for conventional systems. Here, we report a lead-free, vacancy-ordered perovskite Cs2TeCl6, that achieves precise temperature sensing through a novel combination of self-trapped excitons (STEs) photoluminescence (PL) lifetime modulation and unprecedented fifth-order phonon anharmonicity. The STEs PL lifetime demonstrates a highly temperature-sensitive response from 200 to 300 K, ideal for low-to-intermediate thermal sensing.
View Article and Find Full Text PDFACS Nano
January 2025
Center for Terahertz Waves and School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China.
The physical picture for photocurrent injection and coherent control in intrinsic graphene under two-color laser excitation remains obscure. Previously, photocurrent injection of intrinsic graphene was attributed to the quantum interference between two electronic transition pathways of single-photon and two-photon absorptions as well as layer-to-layer coupling. Here, we show that quantum interference between stimulated electronic Raman scattering and single-photon absorption plays a very important role in contributing to the total photocurrent, while interlayer coupling does not sufficiently affect the photocurrent injection, which is in contrast to the previous interpretation of the experimental results on photocurrent injection and coherent control.
View Article and Find Full Text PDFNanophotonics
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 PDFNanophotonics
January 2025
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Sum-frequency generation (SFG) enables the coherent upconversion of electromagnetic signals and plays a significant role in mid-infrared vibrational spectroscopy for molecular analysis. Recent research indicates that plasmonic nanocavities, which confine light to extremely small volumes, can facilitate the detection of vibrational SFG signals from individual molecules by leveraging surface-enhanced Raman scattering combined with mid-infrared laser excitation. In this article, we compute the degree of second order coherence ( (0)) of the upconverted mid-infrared field under realistic parameters and accounting for the anharmonic potential that characterizes vibrational modes of individual molecules.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K.
Understanding the role of structural and environmental dynamics in the excited state properties of strongly coupled chromophores is of paramount importance in molecular photonics. Ultrafast, coherent, and multidimensional spectroscopies have been utilized to investigate such dynamics in the simplest model system, the molecular dimer. Here, we present a half-broadband two-dimensional electronic spectroscopy (HB2DES) study of the previously reported ultrafast symmetry-breaking charge separation (SB-CS) in the subphthalocyanine oxo-bridged homodimer μ-OSubPc.
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