Parametric amplification of light waves at low-frequency pumping in aperiodic nonlinear photonic crystals

A theory of monochromatic light propagation in a fiber amplifier is developed. It is shown that competition between coherent gain-guided modes is qualitatively different from interaction between incoherent beams. Spatial beating between modes limits the gain of the mode with lower input power even if the corresponding modal gain coefficient is higher. Depending on the input beam parameters, the amplifier output can be dominated by either a single guided mode or their combination. The theory is illustrated by analyzing the gain behavior of a single planar waveguide and arrays of two and three narrow planar waveguides.     

Lasers on overtone transitions of carbon monoxide molecule

The experimental and theoretical study of lasers working on the first vibrational overtone of the CO molecule is reviewed. A theoretical model of the active medium of the CO laser and its verification are presented. The CO laser operation in a wide spectral range (2.5–4.2 μm) that spans the atmospheric transparency window is demonstrated in the review of experimental works. It is shown that the overtone CO laser can serve as an effective mid-IR source for atmospheric spectroscopy, long-distance transportation of laser radiation, remote laser sensing, etc.     

Influence of diffusion of the electron energy distribution function in a low-temperature microwave discharge plasma

Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 32, No. 2, pp. 235–241, February, 1989.     

One-Atmosphere Argon Dielectric-Barrier Corona Discharge as an Effective Source of Cold Plasma for the Treatment of Polymer Films and Fabrics

The properties of an ac dielectric-barrier corona discharge in argon under atmospheric pressure were studied and the results of testing of this type of gas discharge in the low-temperature treatment of polymer films and fabrics for the purpose of enhancement of their wettability were reported.     

Synchronizing a chaotic laser by injecting a chaotic signal with a frequency offset

It has been theoretically proven that a chaotic laser driven by an injected signal derived from a similar chaotic master oscillator working at a slight frequency offset operates in a new mode of synchronization. There is a certain relationship between average laser fields, which has been approximately calculated in an explicit form, and instantaneous fields form an attractor about the point defined by these average values, with a relatively small spread in the phase trajectories around it. It has been shown that such a configuration can be used in transmitting confidential information. Zh. éksp. Teor. Fiz. 115, 1593–1604 (May 1999)     

The Measurement of Current Column Plasma Parameters in the Glow Discharge at Increased Pressure

Results of the probe and thermocouple measurements of the constricted stationary glow dis charge in nitrogen and air at pressures up to 60 Torr are given. It was shown that the main energy processes in the column are the heating of the gas and its vibrational excitation. The balance of charged particles is determined by the electron-ion recombination and the stepwise ionization through metastable levels of nitrogen molecules. The results obtained can be used in the numerical simulation of a moving filament during the current constriction in the glow discharge.     

Phase locking in a multicore fiber laser by means of a Talbot resonator

We report phase locking of a diode-pumped multicore fiber laser with a circular array of 18 Nd-doped emitters (microcores) acting as an active medium. Phase locking was achieved in a Talbot resonator configuration. We present calculations of the effective reflection coefficients that are due to self-imaging. Far-field distributions and near-field pattern of several supermodes are calculated and compared with experimental results.