Four-photon Polarization Spectroscopy Research Articles

Four-photon polarization spectroscopy of induced plasma oscillations in a skin layer of semiconductors

Probe-beam scattering spectra have been obtained for four-wave mixing of laser waves in the skin layer of intrinsic semiconductors. The spectra were recorded using the frequency dispersion of orthogonally polarized radiation, which arises as a result of nonlinear optical interaction with conduction-band electrons. The mixing of two counterpropagating light waves in a semiconductor, implemented under nonlinear excitation of longitudinal density oscillations in the plasma electron subsystem of the semiconductor, is theoretically considered. This mixing is shown to lead to the rotation of the probe-beam polarization vector. The results obtained are of interest, e.g., for studying optical metamaterials based on thin-film structures.

Four-photon polarization spectroscopy of the rotational resonances in liquids in the range 0–3 THz

The spectra of the coherent molecular rotation that coincide with the rotational spectra of the corresponding molecules in the gas phase are measured for the first time using four-photon coherent laser spectroscopy in the range 0–100 cm−1 in several liquids (CCl4, H2O2, D2O, and H2O). The measured spectra make it possible to separate the spectral contributions of the slow rotational molecular motions about the equilibrium and the fast rotations. The selectivity of the action of the microwave radiation on biological objects can be increased using the results obtained.

Four-photon laser spectroscopy of low-frequency rotational resonances of H2O molecules in the liquid phase

A clearly pronounced structure of the Rayleigh wing consisting of a great number of components is measured in the range 0–100 cm−1 using four-photon polarization spectroscopy. The features observed are compared with the calculated IR spectra of H2O molecules in the gas phase taken from the HITRAN database. A good correlation between the frequency positions of the observed and calculated lines points to the possibility of hindered rotation of water molecules in liquid.

Four-photon laser spectroscopy of translational vibrations of a proton in water and hexagonal ice

For the first time, translational vibrations of a proton in H2O, D2O, HDO, and hexagonal ice were found in the Rayleigh line wing using four-photon polarization spectroscopy.

Four-photon polarization spectroscopy of water and its isotopic molecules in the spectral range between 0 and 50 cm–1

The four-photon polarization spectra of the Rayleigh wing of water and its isotopic molecules are recorded in the frequency range from 0 to 50 cm–1. New resonances at ±1.4 (in H2O) and ±0.8 cm–1 (in D2O) are found whose nature is not clear as yet. It is shown that the HDO molecule has no rotational resonances in the 50% mixture of H2O and D2O, but H2O and D2O molecules exhibit distinct rotational resonances, which correlates with the data on valence vibrations.

Four-Photon Polarization Spectroscopy of Water and Its Isotopic Molecules in the Spectral Range between 0 and 50 cm[sup –1

Four-Photon Polarization Spectroscopy of Water and Its Isotopic Molecules in the Spectral Range between 0 and 50 cm[sup –1

Four-photon Raman spectroscopy of intermolecular vibrations in water solutions of electrolytes

The influence of electrolyte concentration on the water libration spectrum was studied by four-photon polarization spectroscopy. The results were compared with the data on stretching O–H vibrations observed in spontaneous Raman spectroscopy in water solutions of electrolytes, and a qualitative coincidence of these results was found. It is shown that the weakening of hydrogen bonds at low electrolyte concentrations and the strengthening of coupling between water molecules and ions at high concentrations shift the libration resonances to high and low wavenumbers, respectively. Copyright © 2000 John Wiley & Sons, Ltd.

Ion-Induced Random Electric Fields in Aqueous Salt Solutions as Studied by the Four-Photon Polarization Spectroscopy Method

Using the four-photon polarization spectroscopy we have studied the Rayleigh wing spectral patterns of several aqueous salt solutions within the 0-50 cm

Detection of the structure of the wing of the Rayleigh line in ice, water, and heavy water using four-photon polarization spectroscopy

The spectral structure of the wing of the Rayleigh line in ice, ordinary water (H2O), and heavy water (D2O) is recorded in the frequency range 0–50 cm−1 by means of four-photon polarization spectroscopy. It is shown that this structure can be explained by the collective rotational motion of molecules in cells determined by the structure of hexagonal ice.

Four-photon polarization spectroscopy of water in a millimeter-wave radiation field

Resonance (frequency 1.4 cm(−1) changes induced in the four-photon optical spectrum of water by a millimeter-wave electromagnetic field are observed experimentally. Comparison with the spectrum of ice in the range 0‒2 cm(1 shows that the action of such a field is of a structure-forming character.

Interior structure of degassed water as studied by the four-photon polarization spectroscopy method

Using the four-photon polarization spectroscopy of the Rayleigh wing we observed for the first time that the low-frequency spectrum of degassed water differs from that of non-degassed water. There exist a number of well-pronounced spectral lines within the 5–20 l/cm range for degassed water, whereas those lines are evidently absent for non-degassed water. We assume that the lines correspond to transitions inherent in low-energy quasi-rotational states of water molecules. The absence of those lines in non-degassed water may originate from the fact that the gas, dissolved in water, exists in the form of electrically charged microbubbles and the local electrostatic field arising in water destroys the quasi-rotational lines in the low-frequency spectrum.

Four-photon spectroscopy of collective interactions between water molecules and electromagnetic radiation.

Nine bands of low frequency intermolecular vibrations of liquid water in the range 15\char21{}85 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ have been found with the help of the four-photon polarization spectroscopy method. Quantum theory of collective dipole interaction between water molecules and electromagnetic field have been proposed. The calculated frequencies of the terms are in qualitative and approximate quantitative agreement with the experimental ones.

Four-photon Polarization Spectroscopy of Associated Aqueous Solution in the Vicinity of the Stratification Curve

Abstract A new method of four-photon spectroscopy of the Rayleigh wing has been employed for the first time to study associated aqueous solutions of 2,3,6-trimethylpyridine (TMP). An anomalous behaviour of the spectra is observed at 1 : 3 ratio of TMP and water molecules.