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The problem of one-dimensional propagation of low-frequency electromagnetic waves in homogeneous ionospheric plasma at an angle to the external magnetic field is examined. An oscillating pulse function is obtained for such waves. The shape of the envelope is determined by the Pedersen conductivity. The oscillation period increases with distance and the angle between the propagation direction and the external magnetic field. The period is determined by the Hall and Pedersen conductivities and varies from tenths of a second to seconds.

The generation of the second harmonic (SHG) of an electromagnetic TM wave in a thin parabolic layer of cold plasma under the condition that the region of the plasma resonance at the fundamental or doubled frequency is close to the top of the layer is studied. It is shown that the strongest SHG occurs at resonance at the fundamental frequency. In this case, if collisions are quite weak, the efficiency of SHG at the extremum of the plasma density is much higher than that of SHG in monotonic (both smooth and sharp) plasma layers. For resonance at the doubled frequency the maximum amplitude of the second harmonic is of the same order of magnitude as in the sharply nonuniform monotonic layers.

Numerical simulation has been used to examine the collective state in optical aerosol breakdown, which produces an extended plasma region at anomalously low intensities. The proposed model gives a particular solution to the inverse problem of spark dynamics, which enables one to use parameters readily determined by experiment for the developed breakdown plasma to derive the conditions at or near an aerosol particle, including those before a plasma microregion is formed.

The authors study the resonant transition radiation of a uniformly moving charge in a thin parabolic plasma layer; the transition radiation is caused by the presence of plasma resonance near the extremum of concentration. It is shown that, in a narrow frequency interval near the maximum plasma frequency of the layer, the spectral energy density of the extremal resonant transition radiation exceeds considerably the energy density of radiation, although the total energies of transition radiation are, in both cases, close in magnitude. We consider the possibilities of using this effect for the diagnostics of inhomogeneous plasma.

The thermal blooming of a collimated parabolically scanning beam in a defocusing medium moving across the beam is modeled. It is shown by numerical analysis that the maximum intensity in the beam within a specified portion of the path can be increased significantly by proper selection of the parameters of the scanning trajectory.

A relationship is derived that couples the total energies and frequencies of quasimonochromatic wave packets that propagate in linear systems having parameters that vary in time and space according to the law governing a traveling wave having an arbitrary profile.

The interaction of electromagnetic waves with a uniformly, moving ionization region in immovable medium is considered. It is shown that the reflection and refraction coefficients may be expressed through the corresponding coefficients for the immovable plasma layer of the analogous profile. The relations obtained contain total energies and frequencies of the interacting waves at different velocities of the ionization wave. Unlike the moving inhomogeneous plasma, the total signal energy and the quantum number decrease in all cases.