Ultrafast optical Kerr dynamics studied with incoherent light
Takayoshi Kobayashi1991, The Journal of Chemical Physics
Sign up for access to the world's latest research
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Abstract
Femtosecond optical Kerr dynamics in various transparent liquids were measured using incoherent light with a 60 fs autocorrelation width. From the measurement of the optical Kerr effect (OKE) of binary mixtures of CS2 and various liquids, the contribution of the intermolecular interaction-induced polarizability change to the OKE was found to be affected remarkably by the femtosecond molecular dynamics of CS2. Especially, data from diluted solutions of CS2 in nonviscous solvents composed of molecules with a low molecular weight are consistent with the binary collision model in free space. An oscillatory feature, which was attributed to an intermolecular vibrational mode, was found in the OKE dynamics of neat benzene and several benzene derivatives. A theoretical expression for the delay-time dependence of the signal intensity was also derived with no restriction on the statistical properties of the incoherent light. It is expressed in terms of the autocorrelation function of the inte...
Related papers
Molecular dynamics investigation with the time resolved optical Kerr effect on the CS2–C6H6 mixtures
The Journal of Chemical Physics, 2006
An investigation of the molecular dynamics in pure liquids and in mixtures through the technique of time resolved optical Kerr effect is performed. The samples studied were the mixtures of carbon disulfide (CS2) with benzene (C6H6). The molecular dynamics of the pure liquids is briefly discussed while the main results are obtained for the mixtures. A slow dynamics component is observed for the optical heterodyne detected optical Kerr effect transient decaying exponentially with time constants on picosecond time scale. The fast subpicosend time relaxations are analyzed in terms of the nondiffusive component of the spectral response that is associated with the molecular dynamics. The modifications of the spectrum are quantified, and the explanation of the observed changes is given in terms of the structural interaction configurations that produced changes in the intermolecular potential within which the molecules execute librational motions.
Ultrafast solvent dynamics: Connection between time resolved fluorescence and optical Kerr measurements
1992
The vibrational characteristics of liquid dynamics are used to describe the ultrafast relaxations observed in time-dependent fluorescence Stokes shift [J. Chem. Phys. 95, 4715 (1991)] and heterodyne detected optical Kerr effect measurements on acetonitrile, via a Brownian oscillator model. Introducing a frequency distribution of vibrational modes makes it possible to compare the two experiments. The ultrafast decays observed in the fluorescence Stokes shift and optical Kerr signals are produced by destructive superposition of the high frequency, underdamped modes.
The fast dynamics of benzene in the liquid phase. Part I. Optical Kerr effect experimental investigation
Physical Chemistry Chemical Physics, 2001
Femtosecond heterodyne detected optical Kerr e †ect experiments are performed on liquid benzene in a wide temperature range. Besides the di †usive orientational relaxation, at short times an oscillatory behaviour is observed, superimposed to a faster quasi-exponential decay. The spectral densities obtained by Fourier transform are characterised by a broad band in the region 0È150 cm~1, and their proÐles show a marked temperature dependence. Similar behaviour is observed in a 1 : 6 molar solution of benzene in carbon tetrachloride. The experimental observations can be interpreted by assuming that the basic microscopic system, able to account for the main dynamical properties of the liquid at short times, consists of a benzene molecule librating and oscillating in a "" solvent ÏÏ cage ; consequently, the width of the observed intermolecular vibrational band has an essentially inhomogeneous origin. With the assumption of a bi-modal structure of the frequency distribution, a Kubo treatment is able to reproduce the main features of the experimental spectra at di †erent temperatures. In particular, it is conÐrmed that the peculiar low frequency shape of the spectrum, corresponding to the fast quasi-exponential decay observed in the time-domain experiments, can be attributed to the motional narrowing e †ect. The value of the Kubo correlation time thus estimated ranges between 0.70 q c and 0.25 ps on going from temperatures close to the benzene melting point to near the boiling temperature.
Time-resolved optical Kerr-effect investigation on CS2/polystyrene mixtures
The Journal of Chemical Physics, 2005
The relaxation dynamics of carbon disulfide are investigated in mixtures with polystyrene (PS) using the time-resolved optical heterodyne-detected optical Kerr effect (OHD-OKE). The data are analyzed using both the model-dependent approach, which assumes four distinct temporal responses, and the model-independent Fourier transform approach, which generates a spectral response that can be compared with results obtained by depolarized Rayleigh scattering. A slow dynamics is observed for the OHD-OKE transient decaying exponentially with a time constant that varies from 1.68ps for neat CS2 to 3.76ps for the most concentrated CS2∕PS mixture. The increase of this time constant accompanies an increase in the viscosity of the mixture, so we can associate this component with the diffusive reorientation process of the induced polarizability anisotropy of the carbon disulfide in the mixture. The short-time nuclear response is characterized in the frequency domain by a broad band that peaks aro...
Control of Molecular Dynamics in Benzonitrile and Femtosecond Spectroscopy of the Ultrafast Optical Kerr Effect
Bulletin of the Russian Academy of Sciences: Physics, 2018
The decomposition of the recorded signal of the ultrafast optical Kerr effect (OKE) in benzonitrile into its components corresponding to different molecular contributions is considered. An optical scheme based on two-pulse nonresonant pumping with the registration of a test laser pulse is devised for this purpose.
Time-resolved optical Kerr effect in a fragile glass-forming liquid, salol
1998
PACS. 64.70.Pf -Glass transitions. PACS. 78.20.Jq -Electro-optical effects. PACS. 78.47.+p -Time resolved optical spectroscopies and other ultrafast optical measurements in condensed matter.
Absolute molecular optical Kerr effect spectroscopy of dilute organic solutions and neat organic liquids
Journal of The Optical Society of America B-optical Physics, 2001
We report the results of pump-probe optical Kerr effect (OKE) experiments performed on neat solutions of carbon tetrachloride, nitrobenzene, methyl methacrylate monomer, binary solutions of the squaraine dye indole squarylium, and the phthalocyanine dye silicon phthalocyanine-monomethacrylate, respectively, in carbon tetrachloride, and solid solutions of indole squarylium and phthalocyanine-monomethacrylate in poly(methyl methacrylate). Dispersion measurements of the dye solutions were performed in the visible onephoton resonant region of the dyes defined by their linear-absorption spectra. The dyes' third-order molecular susceptibility response ␥ xxxx (Ϫ 2 ; 1 , Ϫ 1 , 2 ) in this spectral region is markedly different, with R ͕␥ISQ͖ Ͼ 0 and R ͕␥SiPc͖ Ͻ 0. Analysis of the dyes' OKE response requires the inclusion of high-lying two-photon states and suggests that a purely electronic mechanism dominates their OKE response. The results are used to calculate the dyes' off-resonant third-order molecular susceptibilities, which are well within the limits predicted by the Thomas-Reiche-Kuhn sum rule [M. G. Kuzyk, Opt. Lett. 25, 1183-1185].
The Role of Intermolecular Interactions in the Electro-Optical Kerr Effect in Liquid Alkanes
Acta Physica Polonica A, 2005
The electro-optical Kerr effect of n-alkanes from C 5 to C 16 was investigated in gas phase, liquid phase, and solution. The values of the Kerr constants in gas phase are noticeably distinguishable from those in liquids, where the molecules interact by the London dispersion forces. Both the energy of the dispersion interaction and the difference in the Kerr constants in liquid and gas phase grow with molecular size, indicating the key influence of the interaction on the magnitude of the Kerr effect. Several orientation and molecular-statistical theories of electro-optical Kerr effect were applied to model the change in electro-optical Kerr effect due to the dispersion force. Most theories show significant divergence compared to the experimental data. It is argued that the decisive contribution to electro-optical Kerr effect in liquids and the deviations between the experiment and theory arise due to local liquid structures that collectively orient in the external electric field.
Investigating the effects of intermolecular interactions on nonlinear optical properties of binary mixtures with high repetition rate femtosecond laser pulses
Peer J Physical Chemistry, 2022
Measurements of nonlinear optical (NLO) properties of different binary mixtures having carbon disulfide (CS 2) as the common component, namely CS 2-acetone, CS 2cyclopentanone, CS 2-toluene, and CS 2-carbon tetrachloride (CCl 4), are carried out by using the z-scan technique. Open-aperture z-scan (OAZS) and close-aperture z-scan (CAZS) experiments are performed to determine the nonlinear absorption coefficient (β) and nonlinear refractive index (n 2) of all binary liquid mixtures at various compositions of the components by employing a pulsed, high repetition rate (HRR) femtosecond laser. Also, we were able to use the flowing liquid to measure NLO properties in the CS 2-acetone binary mixture to remove the cumulative thermal effects produced due to the pulsed HRR laser light. Nonlinear refractive index (n 2) values are found to be influenced by the weak dipole-induced dipole intermolecular interactions between the nonpolar CS 2 and polar acetone as well as cyclopentanone of the respective binary mixtures. On the contrary n 2 values are not found to be affected by the intermolecular interactions in CS 2-toluene and CS 2-CCl 4 binary mixtures. In comparison, the nonlinear absorption coefficient (β) values are not found to be affected by the same in all different sets of binary mixtures.
Time-resolved optical Kerr effect on a fragile glass-forming liquid: Test of different mode coupling theory aspects
Europhysics Letters (EPL), 2000
The dynamics of the fragile glass-forming liquid m-toluidine is investigated by time-resolved optical Kerr effect. A heterodyne detection technique allows to analyze the signal over four decades in time (10 −13 s to 10 −9 s), in the temperature range 250 K-295 K. The results of data analysis remarkably agree with the predictions of the idealised mode coupling theory (MCT). Some parameters related to that theory are here determined for the first time; also the material-dependent parameters λ = 0.77 ± 0.02 and Tc = 220 ± 5 K can be independently and consistently determined from three different dynamical regimes. Mode coupling theory (MCT) has been found to provide a sensible interpretation of several aspects of the liquid-glass transition of fragile supercooled liquids and in particular of their dynamics at temperatures above the MCT transition temperature T c [1]. Many computer simulations [2] and experiments [3-6] have validated several aspects of this theory, even in its less sophisticated version, the idealised MCT [1]. Although experiments performed in the frequency space [3] have proved to be very useful in the investigation of MCT predictions, experiments performed in the time space in practice provide a more direct comparison with theory. Also, in molecular glass-forming liquids, it is important to disentangle the motion of the centres of mass, for which MCT was originally proposed, from the orientational dynamics, for which theory is less complete [7], though the main results of [1] (see eqs. (3) to (5), below) should presumably apply [8]. This is very difficult to verify in the case of the spin echo technique [4]. There is thus still a need to perform experiments which directly test the orientational dynamics in the 1 ps-1 ns window, on real systems. Recently, a time-resolved non-linear spectroscopic technique, the optical Kerr effect (OKE), which conveniently covers the corresponding time window, has been used for the investigation of the dynamics of a supercooled glass-former liquid [6]. Here we present a study of the
Related topics
Related papers
Molecular librations in a liquid investigated by ultrafast optical Kerr effect spectroscopy
2006
We propose a detail theoretical approach modeling molecular librations in liquid investigated by ultrafast optically heterodyne detected optical Kerr effect (OHD-OKE). The approach has been applied for fluoroform molecular liquid and new information about spectrum, relaxation time and time domain librations has been obtained.
Reorientational and intermolecular dynamics in binary liquid mixtures of hexafluorobenzene and benzene: femtosecond optical Kerr effect measurements
Chemical Physics Letters, 1997
The molecular dynamics of binary liquid mixtures of C6F 6 and C6H 6 were studied by using optical heterodyne-detected Raman-induced Kerr effect spectroscopy (OHD-RIKES) with 45 fs laser pulses at room temperature and ambient pressure. The data give evidence for the effect of interspecies interactions in the short-time, nondiffusive part of the OHD-RIKES response.
Diffusive and oscillatory dynamics of liquid iodobenzene measured by femtosecond optical Kerr effect
Chemical Physics, 1999
The dynamics of liquid iodobenzene are studied by means of time resolved heterodyne detected optical Kerr effect in a wide temperature range ͑263-371 K͒. In the picosecond regime the relaxation is characterized by a biexponential decay, attributed to the rotational diffusion of an anisotropic rotator. The temperature dependence of the two relaxation times agrees only in part with the prediction of the hydrodynamic theory. The subpicosecond dynamics is essentially oscillatory in nature; the Raman spectra obtained by Fourier transform of the time domain data show the contribution of two intramolecular low-frequency vibrations, and that of the intermolecular dynamics. The intermolecular spectra at different temperatures are interpreted on the basis of the Brownian oscillator model, and consist of the superposition of overdamped and underdamped modes. The intermolecular spectrum of the liquid shows a close resemblance with the low-frequency Raman spectrum of crystalline iodobenzene, and suggests an interpretation in terms of collective dynamics with coupling of librational and translational oscillations. The evolution with temperature of the spectra indicates that at high temperature the time-independent picture of the intermolecular modes is not adequate.
Direct Comparison between Ultrafast Optical Kerr Effect and High-Resolution Light Scattering Spectroscopy
Physical Review Letters, 1995
The dynamical response of matter measured by femtosecond optical Kerr effect spectroscopy is directly compared with the high-resolution light scattering spectrum obtained by a tandem Fabry-Perot interferometer. Using simple liquids as samples, we have for the first time confirmed experimentally that the material responses obtained by these timeand frequency-domain measurements completely agree with each other in a frequency region extending over 3 orders of magnitudes.
Molecular dynamics simulations and femtosecond optical Kerr effect spectroscopy of methanol/acetone mixtures
Journal of Molecular Liquids, 2011
Herewith we present the results of our studies on the dynamics of acetone/methanol binary mixtures by means of molecular dynamics simulations and femtosecond optical Kerr effect (OKE) spectroscopy. The OKE response exhibits the apparent dependence on a mole fraction of the mixture components, and thus carries the information about the influence of its composition on the intermolecular interactions and momentary local structures. The molecular dynamics simulations, which take into account the reorientational dynamics of the molecules, have been performed in order to explain the concentration dependence of the long time part of the experimental OKE response.
Ultrafast dynamics of mesoionic liquid solutions studied with incoherent light
Chemical Physics Letters, 2001
Optical Kerr shutter (OKS) measurements were performed in a solution of a mesoionic compound (MIC) in dimethylsulfoxide using 10 ns pulses of broadband noisy light with a coherence time of 160 fs. The results show a light induced birefringence with two main components: an instantaneous one, which follows the laser coherence time, and a sub-picosecond component, with a characteristic time of 560 fs, which is attributed to the birefringence decay due to molecular interactions. Ó
A comparison of the low-frequency spectra of liquids obtained through terahertz, FTIR, and ultrafast optical Kerr-effect spectroscopies
Dynamic solvation of charge-distribution rearrangements is often described using a ͑harmonic͒ solvent coordinate. It is not a priori clear whether such a solvent coordinate has a real physical meaning. We have studied five polar organic liquids ͑benzonitrile, benzyl alcohol, N,N-dimethylformamide, ethylene glycol, and glycerol triacetate͒ with high-resolution high signal-to-noise ultrafast optical heterodyne-detected Raman-induced optical Kerr effect spectroscopy ͑OHD-RIKES͒. The data, converted to the frequency domain, were analyzed entirely with a multimode Brownian-oscillator model. The infrared spectra of the same five liquids were obtained with a combination of terahertz spectroscopy and Fourier-transform infrared spectroscopy. The Brownian-oscillator fits to the OHD-RIKES spectra could be converted successfully to IR spectra by using a simple theoretical model and by keeping all Brownian-oscillator parameters the same except for the amplitudes. This suggests that there is a small set of harmonic oscillators describing ultrafast solvent nuclear dynamics that can be used to understand solvation, IR absorption, and Raman scattering spectra. Recently attempts have been made to use higher-order Raman-like spectroscopies to access hidden information in the solvent Raman bands. 18 -20 It was shown theoretically 21-24 that off-resonant six-and eight-wave mixing experiments can in principle be used to access information that a͒ Electronic
Subpicosecond molecular dynamics studied by degenerate four-wave mixing with incoherent light
Physical Review A, 1987
A time-resolved study of the relaxation times of the third-order susceptibility for the optical Kerr effect in CSz and nitrobenzene was made by degenerate four-wave mixing using 5-ns pulses from a broadband laser. In the case of CS2 we observed both subpicosecond (-0.2 ps) and picosecond (-2 ps) relaxation times for the susceptibility tensor element of P, '» and P, ' both at 553 and 623 nm. The observed relaxation times agree with those obtained utilizing subpicosecond pulses. The relaxation times of nitrobenzene could not be measured because the shorter relaxation time is shorter than the resolution time and the longer one is longer than that of CS~.
Optical-heterodyne-detected induced phase modulation for the study of femtosecond molecular dynamics
The Journal of Chemical Physics, 1991
A new experimental technique for the study of ultrafast optical response of nonlinear materials, which detects nonrelaxational response in the media with high sensitivity, is introduced. Polarization-selective optical-heterodyne-detection scheme is applied to the measurement of the spectral shift of a probe pulse which is caused by induced phase modulation (IPM) brought about by a pump pulse. This technique, being sensitive to the high-frequency component of the nonlinear response, is especially applicable to the study of intermolecular dynamics in disordered media. The temporal responses of the optical Kerr effect in liquid carbon tetrachloride, benzene, and carbon disulfide are studied using this technique with femtosecond optical pulses. In the response of benzene, damped oscillations are clearly observed which are due to intermolecular vibrational motions of the molecules. The data obtained from benzene and carbon disulfide are analyzed using a Fourier-transform method. The resp...
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.