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1

Photoinduced Nonlinear Effects in C_{60}-2-thioxo-1,3-di thiole and C_{60}-TTF Derivatives

100%

Migalska-Zalas A., Fuks-Janczarek I., Dabos-Seignon S., Sahraoui B., Kityk I., Allard E., Kreher D., Cousseau J., Hudhomme P., Gorgue A.

Acta Physica Polonica A

|

2003

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vol. 103

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issue 2-3

283-292

EN

Photoinduced effects in pure C_{60}:C_{60}-TTF and C_{60}-2-thioxo-1,3-dithiole cycloadducts are investigated using nonlinear optical techniques. We have studied photoinduced optical second harmonic generation, two-photon absorption, linear electro-optics, and quadratic electro-optic effect coefficient versus applied pressure (p) and temperature (T). We deduce the influence of the grafted substituents in pure C_{60} on the observed photoinduced effects. The obtained results illustrate clearly that the photoinduced nonlinear optics can be used as a tool to detect structural changes at low temperature in modified C_{60}. We have unambiguously demonstrated that, under the applied hydrostatic pressure up to 19 GPa and the temperature from 4.2 up to 150 K, the observed effects are essentially caused by the grafted TTF derivatives.

2

Circularly Polarized Light-Induced Axial Anisotropy in Achiral Isotropic Media. Magnetic Dipole Interaction with Radiation

63%

Woźniak S.

Acta Physica Polonica A

|

1994

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vol. 85

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issue 6

899-905

EN

The analytical explanation of axial birefringence revealed earlier by the technique of field applied molecular dynamics computer simulation is given. The point group symmetries of achiral molecules admitting the effect are determined and the estimation of the anisotropy is presented. The effect may give information on off-diagonal elements of the Rosenfeld polarizability tensor of achiral molecules.

3

The Third-Order Nonlinear Optical Susceptibility in Octupolar Molecule and its Dipolar Subunit

63%

Derkowska B., Sahraoui B., Nguyen Phu X., Andraud C.

Acta Physica Polonica A

|

2001

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vol. 99

|

issue 1

155-160

EN

The third-order nonlinear optical susceptibility χ^〈3〉 of octupolar molecule with three double bonds was measured using degenerate four wave mixing technique at 532 nm in tetrahydrofuran solution. For comparison, we also measured its analogous dipolar subunit. We found that the χ^〈3〉 value for octupolar molecule is about twice larger than its dipolar subunit.

4

Photoinduced SHG in Push-Pull Chromophores 1,3-dithiol-2-yliedene Moieties Embedded in Photopolymer Matrices

63%

Migalska-Zalas A., Makowska-Janusik M., Kityk I., Sahraoui B., Salle M., Gorgues A.

Acta Physica Polonica A

|

2003

|

vol. 103

|

issue 2-3

293-300

EN

Photoinduced optical second harmonic generation was demonstrated in the several dithiole chromophore molecules with different degree of acceptor function. Theoretical quantum chemical simulations and experimental photoinduced second harmonic generation measurements showed that additional aromatic rings within the dithiole chromophore molecule play an important role in the pump-power dependencies of the second harmonic generation. Varying the presence of the aromatic rings one can achieve substantially different photoinduced second-order nonlinear optical properties.

5

Solute-Solvent Interaction in Aqueous Solutions Studied by Optical Kerr Effect

63%

Błaszczak Z., Farhoud M.

Acta Physica Polonica A

|

1997

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vol. 91

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issue 3

531-541

EN

Solute-solvent interactions were studied by a method based on laser induced optical birefringence in aqueous solutions. The paper reports results of the optical Kerr constant measurements for binary liquid mixtures of aqueous solution of methanol, ethanol, n-propanol and acetone at room temperature in a wide range of concentrations. At 50% concentration of the above mentioned alcohols, the temperature dependence of the laser induced optical birefringence was also measured in the range from 283 K to 315 K. These data together with the density and refractive index were used to calculate the optical and specific Kerr constants. Moreover, these data enabled the calculation of the anisotropic factors, optical anisotropy and orientation function of the substances studied.

6

Resonant Optical Rectification in Chiral Molecular Systems: Application to a Three-Level Model

63%

Woźniak S.

Acta Physica Polonica A

|

1996

|

vol. 90

|

issue 3

519-522

EN

A molecular approach to optical rectification via the imaginary part of the second-order susceptibility related to electric dipole interaction with the radiation field is presented. A quantum-mechanical expression for the frequency dependence of the effect is obtained and its magnitude is estimated in absorption bands of a three-level model.

7

Polaron Effects on Nonlinear Optical Properties of a Hydrogenic Impurity in a CdTe/ZnTe Quantum Dot

51%

Azhagu Parvathi A., John Peter A.

Acta Physica Polonica A

|

2013

|

vol. 124

|

issue 4

706-712

EN

Hydrogenic donor impurity binding energy is obtained in a Zn_{x}Cd_{1-x}Te/ZnTe strained quantum dot taking into account the phonon confinement effect. The interaction of the electron and the phonon modes are expressed in terms of the Fröhlich interaction Hamiltonian. The binding energy is obtained for various Zn composition using the Aldrich-Bajaj effective potential. Calculations have been obtained using the Bessel function as an orthonormal basis for different confinement potentials of barrier height considering the internal electric field induced by the spontaneous and piezoelectric polarizations. Polaron induced linear and third-order nonlinear optical absorption coefficients and the changes of refractive index as a function of incident photon energy are observed. Our results coincide with the recent observations of a hydrogenic impurity binding energy in a CdTe/ZnTe quantum dot solved analytically. It is observed that the potential taking into account the effects of phonon makes the hydrogenic binding energies larger than the obtained results using a Coulomb potential screened by a static dielectric constant and the optical properties of hydrogenic impurity in a quantum dot are strongly affected by the confining potential and the quantum size. It is found that the geometry of the quantum dot, zinc concentration and the effect of phonon have a great influence on the absorption coefficient and refractive index changes of the dot. It is also observed that the magnitude of the absorption coefficients enhances with the inclusion of phonon effect.

8

Third Harmonic Generation Susceptibility of Polyacetylene in Terms of the Chain Temperature

51%

Sabra M.

Acta Physica Polonica A

|

2006

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vol. 109

|

issue 6

761-774

EN

The tight binding Hamiltonian of Su, Schrieffer, and Heeger has been used to describe the physical properties of the polyacetylene chain. The chain temperature is calculated from the potential energy which is directly related to the CH group displacement. Two different forms of the displacements have been considered: random and Gaussian. The third harmonic generation susceptibility spectra have been plotted in terms of the temperature using the four-wave mixing formula. The results show that a second peak at the mid gap energy has occurred for room temperature which is in good agreement with the experimental data.

9

Nonlinear Spectroscopy of Cold, Trapped Atoms

51%

Zachorowski J., Brzozowski T., Pałasz T., Zawada M., Gawlik W.

Acta Physica Polonica A

|

2002

|

vol. 101

|

issue 1

61-75

EN

We report on our studies of atoms contained in a magneto-optical trap using the nonlinear spectroscopy methods. Absorption and four-wave mixing signals are recorded for the probe frequency near the cooling transition frequency and the two methods are compared. The differences in the signal structure and their sensitivity on external conditions are discussed. It is revealed that central feature of these spectra consists of several contributions of different origin.

10

Solvatochromic Effect in a Benzimidazole-Based Betaine: Determination of the Dipole Moments and Second-Order Hyperpolarizability

51%

Ziółek L., Palewska K., Lipiński J., Sworakowski J., Nes̆půrek S., Böhm S., Meister E. C.

Acta Physica Polonica A

|

1995

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vol. 88

|

issue 2

283-293

EN

Results of measurements of the solvent-dependent shift of the low-energy absorption band solvatochromic effect in a benzimidazole-based betaine are reported in the paper. Measurements of absorption spectra in several solvents of different polarities were performed. The solvatochromic shift of the low-lying absorption band was found to exceed 3000 cm^{-1}; the results obtained were then employed to calculate the ground- and excited-state dipole moment of the molecule. The spectroscopic measurements were supplemented by measurements of the ground-state dipole moment. A remarkable change in the charge distribution was found to occur upon the electronic excitation: both the experimental results and the calculations indicate that the ground-state dipole moment is close to 13 D, whereas in the excited state it amounts to ca. 3 D. The second-order hyperpolarizability of the molecule was calculated from the measurements; its off-resonance value amounts to ca. 20 × 10^{-40} m^{4}/V (4.8 × 10^{-30} esu), depending on the solvent used.

Refine search results

Photoinduced Nonlinear Effects in C_{60}-2-thioxo-1,3-di thiole and C_{60}-TTF Derivatives

Circularly Polarized Light-Induced Axial Anisotropy in Achiral Isotropic Media. Magnetic Dipole Interaction with Radiation

The Third-Order Nonlinear Optical Susceptibility in Octupolar Molecule and its Dipolar Subunit

Photoinduced SHG in Push-Pull Chromophores 1,3-dithiol-2-yliedene Moieties Embedded in Photopolymer Matrices

Solute-Solvent Interaction in Aqueous Solutions Studied by Optical Kerr Effect

Resonant Optical Rectification in Chiral Molecular Systems: Application to a Three-Level Model

Polaron Effects on Nonlinear Optical Properties of a Hydrogenic Impurity in a CdTe/ZnTe Quantum Dot

Third Harmonic Generation Susceptibility of Polyacetylene in Terms of the Chain Temperature

Nonlinear Spectroscopy of Cold, Trapped Atoms

Solvatochromic Effect in a Benzimidazole-Based Betaine: Determination of the Dipole Moments and Second-Order Hyperpolarizability