The second hyperpolarizability of CdTe nanocrystals using polarization-resolved degenerate four-wave mixing

Polarization-resolved forward degenerate four-wave mixing (DFWM) in a nonresonant region revealed the effective third-order nonlinear susceptibility of colloidal CdTe nanocrystals (NCs) with the size near the Bohr radius and various concentrations. The second hyperpolarizabilities, and , of the CdTe NCs were ∼1.15 × 10⁻⁴¹ m⁵/V² and ∼3.01 × 10⁻⁴² m⁵/V² from the measurement of the concentration-dependent third-order nonlinear susceptibility of CdTe NCs, respectively. The ratio (/) of the hyperpolarizabilities was ∼0.26, which indicated a large contribution of an electronic polarization process to the third-order nonlinearity of CdTe NCs.     

Threshold kinetic processes for t-C4F9I

A laser oscillator system was used to study the kinetics of t-C₄F₇I relative to n-C₃F₇I. Modeling shows that the rapid R + I¹ recombination results in near steady state gain levels being achieved for t-C₄F₉I while the n-C₃F₇I exhibits strong transient behavior. The estimated recombination rate for t-C₄F₉I is much larger than the published value.     

The induced Raman spectrum of pyridine in solution in carboxylic acids

Induced Raman scattering has been examined for pyridine in solution in formic and acetic acids; intermolecular hydrogen bonds affect the spectrum considerably.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 69–74, September, 1976.We are indebted to Professor F. A. Korolev for constant interest in this work.     

Slow light and superluminality in Kerr media without a pump

Subluminal and superluminal propagation of a light pulse in Kerr materials has been investigated. Group velocities as slow as much less than 1 mm per second to as fast as negative several thousands meters per second can easily be obtained in the Kerr medium, which possesses a large nonlinear refractive index and long relaxation time, such as Cr3+-doped alexandrite, ruby, and GdAlO3. The physical mechanism is the strong highly dispersive coupling between different frequency components of the pulse.     

Effect of complex formation on intensity of stimulated Raman lines in solutions

The intensities of the stimulated Raman lines of pyridine in solutions with proton-donating solvents are measured. The solvents used were: methyl, ethyl, and n-propyl alcohols; water; formic and acetic acids; and also the neutral solvent CCl₄. The intensities of the lines of pyridine in the neutral solvent and in solutions where complexes are formed due to hydrogen bonds differ considerably. This is attributed to the change in the polarizability of the molecules in the complexes and to the competition of the molecules to possess the energy of the exciting light.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 112–116, January, 1976.In conclusion we should like to thank Prof. F. A. Korolev for his constant attention throughout the work.     

An efficient diastereoselective synthesis of novel fused 5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-ones via one-pot three-component reaction

Molecular Diversity - Herein, a convenient and efficient synthesis of 7-benzoyl-6-(aryl)-6,7-dihydro-5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-one derivatives was achieved from the reaction of...