Interferometric Down-Conversion of High-Frequency Molecular Vibrations with Time−Frequency-Resolved Coherent Raman Scattering Using Quasi-CW Noisy Light:  C−H Stretching Modes of Chloroform and Benzene

Abstract

For the first time, the high-frequency symmetric C−H stretching modes of chloroform and benzene are down-converted using the recently developed time−frequency-resolved interferometric coherent anti-Stokes Raman scattering with broad-band nontransform limited (noisy) light excitation method. As an application, chloroform−carbon tetrachloride, benzene−benzene-d6 and benzene−acetone-d6 dilution series are performed. Concentration-dependent Raman frequencies and vibrational dephasing rate constants are observed by this new technique.

Two-Dimensional Electronic Spectroscopy Using Incoherent Light: Theoretical Analysis

“…Because the topological operations performed on the FTC diagrams represent mathematical operations performed on the analytic intensity-level terms, conceptual tools have been developed to connect the topological operations with the mathematical operations. The conceptual tools also allow one to glean considerable physical insight from the FTC diagrams. ,,, …”

“…Although noisy light offers some advantages, it is not as generally useful as its shortpulse counterpart. One exception is coherent anti-Stokes Raman scattering spectroscopy (I (2) CARS), where the noisy-light version has proven to be a very useful tool that is still being used to investigate a variety of systems [87,[102][103][104][105][106][107][108][109][110][111][112][113][114][115][116]. Noisy sources have found occasional uses and advantages in other spectral regimes as well [117][118][119][120][121].…”

“…Because of its phase-incoherent nature, noisy light is an important step closer to sunlight than are femtosecond pulses. In this work we use the well-established technique of factorized time correlation (FTC) diagram analysis [110,112,113,125]-along with direct calculation of the spectroscopic signals-to describe a noisy-light version of two-dimensional electronic spectroscopy (I (4) 2D ES, where I (4) indicates four incoherent beams). The theory is presented and discussed for noisy light interacting with a Bloch four-level system.…”

Light and deuterated acetonitrile: an unresolved casus?

“…The greater efficacy of C-H/D stretching as a probe of its microenvironment, with respect to other normal modes of a molecule, has been reported. 25,28 In our opinion, this is strictly correlated with the particular molecular motion described by this normal coordinate. The symmetric stretching motion spans a relatively small volume in its neighbouring molecular environment, being so particularly selective in its probing.…”

Time-Frequency Resolved Coherent Raman Scattering From Molecular Liquids and Their Mixtures With Quasi-Cw Noisy Light: I(2) CRS Spectrograms

“…More explicitly, in I2)CRS, the Nyquist sampling criterion is significantly reduced. A dramatic example of this is the down conversion of high energy ( 3000cm-1) C--H stretching modes to RDOs from 0-300 cm-1 [6]. Thus, from the I(2)CRS interferograms one is able to extract the material parameters CaR and "YR.…”