Особенности затухания свободной поляризации в ультратонких газовых ячейках

Optical effect of the free polarization decay is studied theoretically in the ultrathin gas cell whose inner thickness is less or order of the wavelength of exciting monochromatic laser pulse transmitted orthogonally to plane-parallel walls of the cell. New mechanism of the investigated effect is established which is caused by specifics of phase mismatch of light induced atomic dipole moments because of transit-time relaxation in such a cell. As a result, dynamics of the free polarization decay in the considered situation radically different from the known case in a usual (macroscopic) gas cell. Nontrivial oscillatory dependences of signals of the free polarization decay on the ratio of thickness of such a cell to the radiation wavelength of the exciting pulse have been discovered and analyzed.

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Внутридопплеровские резонансы затухания свободной поляризации в ультратонких газовых ячейках

Оптика и спектроскопия ◽

10.21883/os.2021.01.50435.238-20 ◽

2021 ◽

Vol 129 (1) ◽

pp. 27

Author(s):

А.Ч. Измайлов

Keyword(s):

Molecular Spectroscopy ◽

High Contrast ◽

Optical Effect ◽

Gas Cell ◽

Ultrahigh Resolution ◽

Frequency Standards ◽

Stationary Radiation ◽

Quantum Transitions ◽

Linear Optical ◽

Free Polarization

The linear-optical effect of the free polarization decay (FPD) in an ultrathin gas cell, the internal thickness of which is less than or of the order of the wavelength of the exciting monochromatic laser radiation, transmitted orthogonally to the plane-parallel walls of this cell, is theoretically investigated. The considered coherent FPD signal is emitted immediately after an abrupt interruption of such a relatively weak stationary radiation. Sub-Doppler resonances arising at the central frequencies of the studied quantum transitions in the spectra of the intensity and energy of the FPD as a result of the transit-time relaxation of atoms in the gas cell are established and analyzed. A significant dependence of these resonances and the dynamics of the FPD on the ratio of the inner thickness of the ultrathin cell to the wavelength of the exciting monochromatic radiation is shown. The narrow, high-contrast sub-Doppler resonances of the FPD detected and investigated in the linear-optical regime can be used in ultrahigh-resolution atomic (molecular) spectroscopy, as well as references for compact frequency standards.

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Collision‐induced atomic dipole moments

The Journal of Chemical Physics ◽

10.1063/1.437802 ◽

1979 ◽

Vol 70 (6) ◽

pp. 3125-3129 ◽

Cited By ~ 10

Author(s):

John Bentley

Keyword(s):

Dipole Moments ◽

Atomic Dipole

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Standardized Medium-Size Basis Sets for Calculations of Molecular Electric Properties: Group IIIA

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20030211 ◽

2003 ◽

Vol 68 (2) ◽

pp. 211-239 ◽

Cited By ~ 57

Author(s):

Ivan Černušák ◽

Vladimir Kellö ◽

Andrzej J. Sadlej

Keyword(s):

Reference Data ◽

Dipole Moments ◽

Relativistic Effects ◽

Basis Set ◽

Basis Sets ◽

Medium Size ◽

Polarized Basis Sets ◽

First Order ◽

Atomic Dipole ◽

High Level

The idea of what is called the basis set polarization method is reviewed and the available polarized basis sets are surveyed. Following the basis set polarization approach and certain empirical rules developed earlier, the first-order polarized basis sets for the Group IIIA elements are generated. These basis sets have been developed for both nonrelativistic and spin-averaged Douglas-Kroll relativistic calculations. Their performance is tested in calculations of atomic dipole polarizabilities and in high-level-correlated calculations of the dipole moments of GaF, InF, and TlF. The relativistic effects have been found to significantly affect the calculated molecular dipole moments of the studied fluorides. The results are in satisfactory agreement with reference data. The present study completes the library of the first-order polarized basis sets for all atoms of the main groups of the Periodic Table.

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Atomic dipole moments calculated using analytical molecular second-moment gradients

The Journal of Chemical Physics ◽

10.1063/1.1738631 ◽

2004 ◽

Vol 120 (22) ◽

pp. 10368-10378 ◽

Cited By ~ 3

Author(s):

Harald Solheim ◽

Kenneth Ruud ◽

Per-Olof Åstrand

Keyword(s):

Dipole Moments ◽

Second Moment ◽

Atomic Dipole

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Rapid Optical Spin Initialization of a Quantum Dot in the Voigt Geometry Coupled to a Two-Dimensional Semiconductor

Applied Sciences ◽

10.3390/app10031001 ◽

2020 ◽

Vol 10 (3) ◽

pp. 1001

Author(s):

Dionisis Stefanatos ◽

Vasilios Karanikolas ◽

Nikos Iliopoulos ◽

Emmanuel Paspalakis

Keyword(s):

Laser Pulse ◽

Quantum Dot ◽

Field Strength ◽

Continuous Wave ◽

Dipole Moments ◽

Decay Rates ◽

Field Excitation ◽

Short Time ◽

Space Vacuum

We study the interaction of a quantum dot in the Voigt configuration with a laser pulse and particularly analyze the potential for rapid spin initialization by putting the quantum dot near a molybdenum disulfide (MoS 2 ) monolayer. The MoS 2 monolayer influences the spontaneous decay rates of the quantum dot, leading to anisotropically enhanced decay rates, for the quantum dot’s electric dipole moments parallel and perpendicular to the layer. By solving the relevant density matrix equations, we find that high spin initialization fidelity is obtained at short times. The fidelity is significantly higher than when the quantum dot is in free-space vacuum. We examine two different cases of the interaction of the quantum dot with the applied optical field. First, we use a continuous wave laser field and determine for various quantum dot—MoS 2 layer distances the field strength that leads to acceptable fidelity levels. The effect of the quality of the MoS 2 material on the fidelity of spin initialization is also examined. We also study the interaction of the quantum dot with a laser pulse and apply numerical optimal control to obtain the time-dependent field strength, which leads to maximum final fidelity for short time intervals. The latter approach gives beneficial results in comparison to the continuous wave field excitation.

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Photolysis of a protecting group for the carboxyl function of neurotransmitters within 3 microseconds and with product quantum yield of 0.2

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.90.23.11074 ◽

1993 ◽

Vol 90 (23) ◽

pp. 11074-11078 ◽

Cited By ~ 19

Author(s):

D Ramesh ◽

R Wieboldt ◽

L Niu ◽

B K Carpenter ◽

G P Hess

Keyword(s):

Quantum Yield ◽

Laser Pulse ◽

Cortical Neurons ◽

Glycine Receptor ◽

Glycine Receptors ◽

Blocking Group ◽

Biological Assays ◽

Cell Current ◽

A Cell ◽

Kinetic Investigations

The synthesis of a photosensitive blocking group for the carboxyl function of neurotransmitters, in this case glycine, is reported. The compound, 2-methoxy-5-nitrophenyl glycine ester (caged glycine), is photolyzed by a laser pulse at 308 or 337 nm within 3 microseconds and with a product quantum yield of 0.2. The compound is hydrolyzed in water with a time constant tau of 6.1 min at pH 7.1 and 3 hr at pH 4.0. Mouse cerebral cortical neurons containing glycine receptors were used in biological assays. A cell-flow device, in which solutions of caged glycine at pH 4.0 were mixed with buffer to give a final pH of 7.1, was used to equilibrate the compound with receptors on the cell surface. Neither the caged compound nor the 2-methoxy-5-nitrophenol photolysis product affected the glycine receptors or modified their response to glycine. When cells equilibrated with caged glycine are irradiated by a laser pulse at 337 nm, glycine receptor channels are opened, as detected in whole-cell current recordings. The approach described may be used in the synthesis and characterization of photolabile precursors of neurotransmitters and other compounds that contain carboxyl groups and for kinetic investigations of neurotransmitter receptors in central nervous system cells in the microsecond time domain.

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