A. S. Biryukov

Classical field theory methods in laser physics. I. Radiation field in empty resonators and resonators with inhomogeneous active medium

One of the possible interpretations of laser radiation inside a resonator is given. It is based on the method of normal coordinates. In the course of presentation, the method is gradually complicated. This is accompanied by refinement of the interpretation of laser radiation in a resonator.

Classical field theory methods in laser physics. III. Propagation of laser radiation in vacuum outside a resonator

The third Part of our work continues the analysis of the problem considered in Parts I and II [J. Russ. Laser Res.,17, 205 (1996);18, 2 (1997)]. We continue the search for the answer to the question: What is laser radiation from the viewpoint of the classical theory of wave fields? Here, we give one of the possible interpretations of propagation of laser radiation in vacuum outside a resonator from both the nonrelativistic and relativistic points of view. The relation between the metric and the radiation field structure is noted. Moreover, the third Part contains the conclusion concerning the work as a whole. It presents the main observations that may be useful for further studies of the problem.

Effect of electric field on activated sludge in water

The results of the study of the effect of a dc electric field on activated sludge of aeration tanks. It is experimentally detected that the specific oxidation rate of organic compounds by activated sludge increases up to 90.5% with electric field processing, and then decreases. The observed effect is substantiated. The results obtained can find wide application in purification of sewage polluted by organic compounds.

Theoretical feasibility study of new high-efficiency continuous-wave lasers operating at electron transitions in the spectral regions from near ir to uv on the basis of unconventional mechanisms of forming the active gaseous media

This paper is a review of the results of theoretical studies related to the search for new mechanisms, which are not yet completely understood and have not been implemented so far, of forming the active laser media that offer the prospect of development of high-efficiency continuous-wave (cw) laser operating at electron transitions (in atoms or molecules) in a wide range of wavelengths (from near IR to UV). The main attention is paid to unconventional mechanisms of forming the population inversion of lasing-active levels. These mechanisms involve the intramultiplet (due to collisions with heavy particles) or ionization-induced (due to collisions with electrons) deactivation of the lowest lasing-active atomic level; the population of the upper lasing-active level as a result of three-body electron-ion recombination induced by the presence of alkali impurity, with simultaneous intramultiplet decay of the lower level; the mechanism ensuring the lasing transitions between repulsing terms of the involved molecules; and the exchange of vibrational-electronic excitation (for example, exchange of two vibrational quanta of an excited hydrogen molecule for a single electronic quantum of the iodine atom).

Ecological aspects of water. A quick-test method for determination of biochemical consumption of oxygen in aqueous systems with organic contamination

A number of fundamental issues related to the ecology of water (the indices of the quality of natural and waste water, the main phases in the development of microorganisms, the role of enzymes, the basics of the conventional method for determining the biochemical consumption of oxygen (BCO), biophysical models, and so on) are considered. A new quick-test method for determining the BCO in aqueous solutions is suggested and validated. This new method is extended to the case of multicomponent organic contaminants. A kinetic model of enzymatic extracellular hydrolysis of organic compounds is developed.

On the Pulse Shape of a Radiation Wave Diffracted by a Slit

A simple method for describing the evolution of the longitudinal component in a laser-rdiation pulsed wave diffracted by a slit is outlined. The method is based on the concept of curved space and is illustrated by the example of radiation pulse diffraction by a slit, with the pulse having a Gaussian shape before entering the slit. The merits of the chosen method of analysis are listed.

Classical field theory methods in laser physics II. Statistical methods of laser physics

The second part of our work continues the analysis of the problem studied in the first par [J. Russ. Laser Res.,17, 205 (1996)]. We seek an answer to the following question: What is laser radiation from the viewpoint of the classical theory of wave fields? Here, we consider the statistical aspect of the problem. Moveover, we show how this aspect is connected with the formation of laser radiation from the level of spontaneous noise and how it governs the quality of laser radiation.

On the Diffraction of a Pulsed Wave by a Slit

A new interpretation of the pulsed wave diffraction by a slit is given. The interpretation is based on the representation of the diffraction within the framework of a new method of local oscillation frequencies. The method is used to analyze the radiation field structure described in terms of the Laplace-Beltrami wave equation and the Einstein equations for weak gravitational fields in a curved space. It is found that, under assumptions corresponding to the method of local-oscillation frequencies, the energy-conservation law breaks down in the radiation field defined by the Einstein equations. An analysis of transverse structure of radiation in the far-field zone using the Laplace-Beltrami wave equation yielded results that agree satisfactorily with the known results of experimental and theoretical studies.

Methods of estimating the angular and energy characteristics of generated laser emission

The physical models used to estimate the angular and energy characteristics of laser emission generated in the kinetic and coherent regime of emission interaction with an active medium are critically analyzed and systematized.