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A nonstationary regime of squeezed-light generation by a single-atom laser is investigated. Dependences of the quantum-squeezing parameter and radiation intensity on modulation frequency of the atom–field coupling constant are obtained. It is demonstrated that a resonance appears at the modulation frequency equal to twice the average coupling constant, which leads to a more efficient quantum squeezing in a nonstationary harmonic regime than in the case of a stationary regime for the same values of the relaxation and pump parameters.

The optical orientation of the angular momenta of alkali atoms in the presence of a buffer gas (molecular nitrogen) has been studied experimentally. It has been shown that, even at a low concentration of molecular nitrogen in the cell, the excitation of 133Cs atoms from the lower hyperfine level with F = 3, which belongs to the ground 2S1/2 state, results in a larger amplitude of the magnetic resonance than the excitation from the hyperfine level with F = 4. This result has been theoretically explained under the assumption that the spin state of the alkali atomic nucleus does not change at collision with a nitrogen molecule, which is accompanied by a nonradiative transition of the alkali atom from the excited 2P1/2 state to the ground 2S1/2 state.

The Lande factors of hyperfine sublevels belonging to the same spectral term differ from each other. This leads to the appearance of an effective gyromagnetic ratio for an atomic ensemble, which can be defined as the ratio of the average magnetic moment to the average angular momentum. Characteristically, this quantity is not a constant, but rather depends on the populations of the hyperfine sublevels. States of an ensemble of atoms occupying their ground level in which the effective gyromagnetic ratio is zero are of much interest. Here, one of such states is considered by the example of alkali metal 87Rb. The main idea is to suggest a method for preparing states with zero effective gyromagnetic ratio by means of two-frequency pumping of a saturated alkali-metal vapor in a cell containing a buffer gas. It is noteworthy that, according to calculations, correlation between the two fields is not required for attaining this goal.

The hydrophosphorylation of monosaccharides oximes and hydrazones was studied; similarity and difference of this process compared to the reaction of secondary glycosylamines with the hydrophosphoryl compounds are shown. A number of the original α-aminophosphoryl compounds is obtained including those containing carbohydrate fragment in their compositions.

An original method of synthesis of optically active α-aminophosphoryl compounds containing a carbohydrate residue is proposed.

The products of crystallization of 4-hydroxybenzaldehyde-4-nitrophenylhydrazone (I) and N′-(2-phenyl-1H-indole-3-aldehyde)-4-nitrophenylhydrazone (II) from different solvents are studied by X-ray diffraction with the aim of examining the polymorphism of hydrazone derivatives. The structural features of the crystals prepared are analyzed. It is shown that, in the case when molecules of organic compounds with a high molecular hyperpolarizability are capable of forming stable acentric supramolecular associates in the crystal, knowledge of their polymorphism offers strong possibilities for designing the noncentrosymmetric crystal structure necessary for a manifestation of the nonlinear optical activity.

The derivatives of 3-(4-nitrophenyl)-2-phenylacrylic acid are synthesized. It is shown that the chemical modification of this acid results in a change in the symmetry of the supramolecular fragment formed by molecules in the crystal. In turn, this change leads to a change in the crystal symmetry and favors the formation of a noncentrosymmetric crystal structure. The crystal structures of 3-(4-nitrophenyl)-2-phenylacrylic acid (I), 3-(4-nitrophenyl)-2-phenyl-triethyl aminoacrylate (II), and 3-(4-nitrophenyl)-2-phenylacrylic acid (3-methoxy)phenyl ester (III) are investigated by X-ray diffraction.