Novel interface‐selective even‐order nonlinear spectroscopy

Yamaguchi, S.; Tahara, Tahei

doi:10.1002/lpor.200710027

Cited by 20 publications

(13 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sum frequency generation (SFG) spectroscopy enables the microscopic investigation of liquid interfaces as thin as a few molecular diameter thickness. 6,[10][11][12][13][14][15] The interface selectivity of SFG is based on the tensorial property of the secondorder nonlinear optical susceptibility ( χ (2) ) under the electric dipole approximation: χ (2) is zero in the centrosymmetric bulk, but it can be nonzero at an anisotropic interface. Secondorder nonlinear polarization given by the product of χ (2) and two input electric fields is localized at the interface, and this polarization is the source of sum frequency (SF) signal light.…”

Section: Introductionmentioning

confidence: 99%

Development of single-channel heterodyne-detected sum frequency generation spectroscopy and its application to the water/vapor interface

Yamaguchi

2015

The Journal of Chemical Physics

112

124

View full text Add to dashboard Cite

Single-channel heterodyne-detected sum frequency generation (HD-SFG) spectroscopy for selectively measuring vibrational spectra of liquid interfaces is presented. This new methodology is based on optical interference between sum frequency signal light from a sample interface and phase-controlled local oscillator light. In single-channel HD-SFG, interferometric and spectrometric measurements are simultaneously carried out with an input IR laser scanned in a certain wavenumber range, which results in a less task than existing phase-sensitive sum frequency spectroscopy. The real and imaginary parts of second-order nonlinear optical susceptibility (χ((2))) of interfaces are separately obtained with spectral resolution as high as 4 cm(-1) that is approximately six times better than existing multiplex HD-SFG. In this paper, the experimental procedure and theoretical background of single-channel HD-SFG are explicated, and its application to the water/vapor interface is demonstrated, putting emphasis on the importance of a standard for the complex phase of χ((2)).

show abstract

Section: Introductionmentioning

confidence: 99%

Development of single-channel heterodyne-detected sum frequency generation spectroscopy and its application to the water/vapor interface

Yamaguchi

2015

The Journal of Chemical Physics

112

124

View full text Add to dashboard Cite

show abstract

“…Interfacial regions have a thickness of only a few molecular diameters, but they are critically important environments for many fundamental physicochemical and biological processes. [1][2][3] The distinct anisotropy across an interface greatly influences molecular properties such as structure, 4-8 polarity, [9][10][11][12][13] pH, [14][15][16][17][18] friction, 19,20 and dynamics. [21][22][23][24][25] Solute molecules adsorbed at liquid interfaces experience significantly different local environments from those in bulk liquid phases, which can make chemistry at interfaces markedly different.…”

Section: Introductionmentioning

confidence: 99%

“…To investigate the unique properties of liquid interfaces, the combination of appropriate probe molecules and interface-selective even-order nonlinear spectroscopies is very effective. 9,12 For example, the polarity of the air/water and water/organic solvent interfaces has been studied by examining electronic spectra of interface-active polarity indicators such as coumarins and nitrobenzene derivatives using interface-selective second harmonic generation (SHG) spectroscopy. 9,11 The pH of aqueous interfaces was also interrogated by studying surface-active pH indicators with SHG.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast dynamics of malachite green at the air/water interface studied by femtosecond time-resolved electronic sum frequency generation (TR-ESFG): an indicator for local viscosity

2010

View full text Add to dashboard Cite

show abstract

“…In order to probe an electronic resonance, SHG requires to tune the laser photon energy and, thus, the spectra consist of discrete points and good energy resolution is achieved at the expense of the acquisition time. Furthermore, timeresolved SHG experiments are often performed at one particular resonance energy and are seldomly frequencyresolved 20 . In this Letter, we present an extension of time-resolved broadband sum frequency generation to the regime of electronic transitions for solid state samples: Timeresolved electronic sum-frequency generation (tr-eSFG).…”

mentioning

confidence: 99%

“…The WLC, ranging from 1.77 to 2.48 eV, is generated by focusing 5 % of the RegA output power into a 3 mm thick sapphire crystal, after rotating it to s-polarization with a λ/2 waveplate. As the group velocity dispersion of light increases with increasing frequency and therefore a broadband visible pulse is more strongly dispersed in time than a broadband IR pulse, time-dependent eSFG 20 is challenging compared to vSFG. To overcome this limit to the temporal resolution, we compress the WLC with a deformable mirror as described in Ref.…”

mentioning

confidence: 99%

Ultrafast dynamics in solids probed by femtosecond time-resolved broadband electronic sum frequency generation

Foglia

Wolf

Stähler

2016

Applied Physics Letters

View full text Add to dashboard Cite

Time-resolved sum-frequency generation is an established tool to investigate ultrafast vibrational dynamics with surface and interface specificity. We present an extension of the technique to the regime of electronic transitions based on a compressed white light continuum. It is used to probe the non-equilibrium dynamics of excitonic resonances in the non-centrosymmetric oxide ZnO, where we demonstrate that we can probe transient changes of the electronic sum frequency generation signal as small as 0.6%.Second-order non-linear optical spectroscopies base on the wave-mixing phenomena that can occur in a material due to the second-order non-linear polarizationacting as the source term for a third electric field E(ω s ) at the sum-or difference-frequency ω s = ±ω 1 ± ω 2 as given by energy and momentum conservation 1-3 . The amplitude of this field depends on the third-rank tensor χ (2) , which reflects the symmetry of the material and vanishes for systems with inversion symmetry. Additionally, P (2) is enhanced whenever at least one of the incoming or generated electric fields is resonant with an optical transition between electronic or vibrational energy levels in a material 3 . Thus, second order non-linear optical effects constitute a unique tool for the spectroscopy of electronic and vibrational states with symmetry specificity. In particular, for centrosymmetric materials and in the dipole approximation, second-order non-linear spectroscopies are intrinsically surface and interface specific, since these break the inversion symmetry 2 . Also, they are sensitive to phase transitions between centrosymmetric and non-centrosymmetric phases as well as between different non-centrosymmetric crystal structures 4 . The combination of non-linear optical spectroscopies with a third laser beam in a "pump-probe" scheme additionally allows to achieve time resolution in the femtosecond range and thereby access the ultrafast timescales of electronic and vibrational processes following photoexcitation in most materials. The sample is photoexcited by a first laser pulse, the "pump", which alters the optical and electronic properties. These pump-induced changes affect the polarization and can be monitored by the nonlinear probe as a function of the time delay after photoexcitation. In this way, second-order non-linear optical effects can be used to probe the dynamics of processes such as solvation 5 , molecular orientation and motion 6-9 , The challenge of non-linear optical spectroscopy is that second-order susceptibilities are 9 to 11 orders of magnitude smaller than linear susceptibilities and, when aiming at time-resolved measurements, the expected pumpinduced signal variation is usually 10% of this already small signal. In other words, for typical pulse energies of 1-5 µJ and at 40 kHz repetition rate, the change of the number of photons impinging on the detector is on the order of few tens of photons per second of exposure. In order to minimize the acquisition time and to optimize the signal to noise ratio and energy resol...

show abstract

Novel interface‐selective even‐order nonlinear spectroscopy

Cited by 20 publications

References 65 publications

Development of single-channel heterodyne-detected sum frequency generation spectroscopy and its application to the water/vapor interface

Development of single-channel heterodyne-detected sum frequency generation spectroscopy and its application to the water/vapor interface

Ultrafast dynamics of malachite green at the air/water interface studied by femtosecond time-resolved electronic sum frequency generation (TR-ESFG): an indicator for local viscosity

Ultrafast dynamics in solids probed by femtosecond time-resolved broadband electronic sum frequency generation

Contact Info

Product

Resources

About