Coherent anti-Stokes Raman scattering: Spectroscopy and microscopy

El-Diasty, Fouad

doi:10.1016/j.vibspec.2010.09.008

Cited by 104 publications

(60 citation statements)

References 206 publications

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“…[5][6][7][8][9][10][11][12] This probe technique has been developed as a variant of fs time-resolved CARS (tr-CARS), [13][14][15][16][17][18][19][20][21][22][23][24][25] the history of which has been described thoroughly in recent reviews. 26,27 Hybrid fs/ps CARS utilizes the same four-wave-mixing excitation scheme as does fs tr-CARS; however, the use of a time-delayed, narrowband, ps-duration probe pulse-rather than a broadband, fs-duration probe pulse-allows direct frequency-domain detection of Raman-active molecular states. 1,3 As such, this detection approach retains the chemical specificity associated with Raman spectroscopy 1,3 with excellent detection sensitivity.…”

Section: Introductionmentioning

confidence: 99%

Time- and frequency-dependent model of time-resolved coherent anti-Stokes Raman scattering (CARS) with a picosecond-duration probe pulse

Stauffer¹,

Miller²,

Slipchenko³

et al. 2014

The Journal of Chemical Physics

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The hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) technique presents a promising alternative to either fs time-resolved or ps frequency-resolved CARS in both gas-phase thermometry and condensed-phase excited-state dynamics applications. A theoretical description of timedependent CARS is used to examine this recently developed probe technique, and quantitative comparisons of the full time-frequency evolution show excellent accuracy in predicting the experimental vibrational CARS spectra obtained for two model systems. The interrelated timeand frequency-domain spectral signatures of gas-phase species produced by hybrid fs/ps CARS are explored with a focus on gas-phase N2 vibrational CARS, which is commonly used as a thermometric diagnostic of combusting flows. In particular, we discuss the merits of the simple top-hat spectral filter typically used to generate the ps-duration hybrid fs/ps CARS probe pulse, including strong discrimination against non-resonant background that often contaminates CARS signal. It is further demonstrated, via comparison with vibrational CARS results on a time-evolving solvated organic chromophore, that this top-hat probe-pulse configuration can provide improved spectral resolution, although the degree of improvement depends on the dephasing timescales of the observed molecular modes and the duration and timing of the narrowband final pulse. Additionally, we discuss the virtues of a frequencydomain Lorentzian probe-pulse lineshape and its potential for improving the hybrid fs/ps CARS technique as a diagnostic in high-pressure gas-phase thermometry applications. The hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) technique presents a promising alternative to either fs time-resolved or ps frequency-resolved CARS in both gas-phase thermometry and condensed-phase excited-state dynamics applications. A theoretical description of time-dependent CARS is used to examine this recently developed probe technique, and quantitative comparisons of the full time-frequency evolution show excellent accuracy in predicting the experimental vibrational CARS spectra obtained for two model systems. The interrelated timeand frequency-domain spectral signatures of gas-phase species produced by hybrid fs/ps CARS are explored with a focus on gas-phase N 2 vibrational CARS, which is commonly used as a thermometric diagnostic of combusting flows. In particular, we discuss the merits of the simple top-hat spectral filter typically used to generate the ps-duration hybrid fs/ps CARS probe pulse, including strong discrimination against non-resonant background that often contaminates CARS signal. It is further demonstrated, via comparison with vibrational CARS results on a time-evolving solvated organic chromophore, that this top-hat probe-pulse configuration can provide improved spectral resolution, although the degree of improvement depends on the dephasing timescales of the observed molecular modes and the duration and timing of the narrowba...

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Section: Introductionmentioning

confidence: 99%

Time- and frequency-dependent model of time-resolved coherent anti-Stokes Raman scattering (CARS) with a picosecond-duration probe pulse

Stauffer¹,

Miller²,

Slipchenko³

et al. 2014

The Journal of Chemical Physics

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“…In the simplest conventional one-dimensional (1D) time-domain stimulated Raman technique, the molecule is first prepared in a vibrational superposition state by an off-resonant Raman pulse and, after a variable delay period T , the transmission change of a second probe pulse is detected. The transmission oscillates with T between gain and loss at the vibrational period, and a Fourier transform then reveals the vibrational frequencies [14][15][16]. Optical Raman techniques have been applied to study electron transfer and nonadiabatic dynamics at conical intersections.…”

Section: Introductionmentioning

confidence: 99%

Detecting electronic coherence by multidimensional broadband stimulated x-ray Raman signals

2015

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Nonstationary molecular states which contain electronic coherences can be impulsively created and manipulated by using recently-developed ultrashort optical and X-ray pulses via photoexcitation, photoionization and Auger processes. We propose several stimulated-Raman detection schemes that can monitor the phase-sensitive electronic and nuclear dynamics. Three detection protocols of an X-ray broadband probe are compared -frequency dispersed transmission, integrated photon number change, and total pulse energy change. In addition each can be either linear or quadratic in the X-ray probe intensity. These various signals offer different gating windows into the molecular response which is described by correlation functions of electronic polarizabilities.Off-resonant and resonant signals are compared. * kdorfman@uci.edu 1 arXiv:1506.08226v1 [physics.chem-ph]

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“…Femtosecond time-resolved CARS is a method for clarifying the origin of ultrafast dynamics associated with molecular motions in liquid [1] in the time domain since 1980s for some decades [2,3]. This technique has been widely used in different samples, such as polydiacetylene [4,5], porphyrin [6,7], toluene [8], methanol-water [9], flame [10][11][12], N 2 [13] and dipicolinic acid [14][15][16].…”

Section: Introductionmentioning

confidence: 99%