Extension of the Sommerfeld diffraction integral to the case of extremely short optical pulses

The Sommerfeld diffraction theory is extended to the case of extremely short pulses. It is shown that a simple qualitative analysis and a quantitative solution of a wide class of diffraction problems are possible for pulses with durations of the order of the period of the light oscillations and an arbitrary initial distribution of the light field. Pis’ma Zh. éksp. Teor. Fiz. 66, No. 5, 323–326 (10 September 1997) Deceased     

Electronic spectra of certain metal nitrates in the vacuum ultraviolet region

Journal of Applied Spectroscopy -     

Self-modulation and nonlinear diffraction of strong light fields in dispersive media

The problem of space-time self-modulation of strong laser fields is solved by the method of successive approximations. The nonlinear diffractional and nonlinear dispersive transformations of beam width and pulse duration are studied with emphasis on the reciprocal effects of nonlinear diffraction and dispersion. The effect of incomplete initial time and space coherence on the space-time parameters of a laser field and the conversion of its coherent properties is examined.Moscow State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 35, No. 6/7, pp. 525–532, June–July, 1992.     

Localized surface waves at the interface between the linear dielectric and photorefractive medium with drift and diffusion nonlinearity

We consider the propagation of the laser beam near the interface between the linear dielectric and photorefractive medium with drift and diffusion nonlinearity. We demonstrated the possibility of the surface waves formation, found the profiles of such surface modes and investigated waveguiding properties of the dielectric-photorefractive medium boundary. The effective particle theory was used to derive an ordinary differential equation that describes the beam center trajectory during the reflection from the interface.     

Electron excitation energy transfer in Me7Eu2UO2(PO4)5 (Me — Na, Rb, Cs) crystals

The article considers the luminescence-kinetics properties of crystals of ternary uranyl orthephosphates Me₇Eu₂UO₂(PO₄)₅ (Me — Na, Rb, Cs) obtained by the methods of solid-phase synthesis. The main parameters of conversion of the electron excitation energy in the donor-acceptor UO ₂ ²⁺ —Ln³⁺ system are determined. The competition between the processes of nonradiative dissipation and energy transfer from UO ₂ ²⁺ to Eu³⁺ has been revealed. It is shown that the rate of the processes of nonradiative transitions in the uranyl complex is determined by the degree of distortion of its local field, while the luminescence lifetime of the acceptors depends on the energy of electrostatic interaction between Eu³⁺ and oxygen atoms of its first coordination sphere. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 333–335, May–June, 2000.     

Spectroscopic characteristics of activated tungsten phosphate glasses in the VUV region

Absorption, reflection, excitation, and quantum yield spectra of the luminescence of Eu³⁺-activated tungsten phosphate glasses were investigated within the range 30,000–95,000 cm⁻¹. It is shown that the differences between the ligands in the first coordination sphere of tungsten and the effects of their mutual influence are responsible for the appearance of tungsten groups WO ₂ ²⁺ with an increased multiplicity of the tungsten—oxygen bond. The spectroscopic properties of tungsten complexes are associated with electron transitions from three completed orbitals that have the character of transitions with charge transfer from the ligands to the coordinating center. This leads to a kind of localization of excitation in the WO ₂ ²⁺ group and ensures constancy of the quantum yield of luminescence in a wide spectral range. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 433–435, July–August, 2000.     

Electron spectra of Me7Eu2UO2(PO4)5 crystals

Absorption and luminescence spectra of Me₇Eu₂UO₂(PO₄)₅ crystals (Me represents Na, Rb, or Cs) are investigated. It is established that the luminescence of Eu³⁺ ions in these crystals is sensitized by uranyl. The effect of the outer-sphere cation Me⁺ on the spectroscopic properties and structural features of the compounds under study is considered. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 89–94, January–February, 1999.