On a method of microwave measurement of ozone

A procedure for determination of the ozone total content and the vertical profile at altitudes of 20–50 km from microwave measurement data is considered. Estimates of possible errors are made, and suggestions aimed at reduction of these errors are considered.Institute of Applied Physics, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 8, pp. 751–770, August, 1995.     

On The “Nonresonance” Parametric Cyclotron Radiation

We study the effect of amplification of coherent bichromatic radiation due to its cyclotron parametric interaction with a modulated ensemble of classical electron oscillators. The mechanism of energy exchange between the radiation and the electrons in the absence of partial synchronism of the waves and particles is analyzed. The features of the energy exchange in the course of interaction of the waves with relativistic and nonrelativistic particles are pointed out.     

On the Theory of “Inversionless” Free-Electron Maser

We develop a linear theory of cyclotron parametric instability in systems that are classical analogs of quantum inversionless lasers. Interaction of bichromatic radiation with an ensemble of classical electron oscillators having a modulated distribution function is considered taking into account that the cyclotron-resonance conditions is valid both for each of the two spectral components at high harmonics and for their beat wave. It is shown that the ballistic restructuring of the modulated fraction of the electrons leads to stabilization of the instability. In this case, a peculiar nonreciprocal regime of the parametric particle-field interaction is realized in which the evolution of the high-frequency wave is independent of the low-frequency mode, though the former wave affects the behavior of the latter one.     

Electromagnetically induced transparency and lasing without inversion in three-level atoms imbedded in a frequency-dependent environment

The response of a three-level atomic system driven by a resonant coherent field acting on a transition near the photonic band-edge of a photonic band-gap material as well as the general case of a frequency-dependent reservoir is studied. The strong frequency dependence of the radiation mode spectral density on the scale of the driving field Rabi frequency is shown to lead to essential and controllable changes in the refractive index, as well as to effects of electromagnetically induced transparency and lasing without inversion. Such an effective dynamic control of the atomic response enables for applications in nonlinear optics and optical computing and communications.     

Numerical Modeling of the Process of Parametric Generation of the Cyclotron Radiation in a Reactive Medium

We present the results of numerical modeling of the effect of amplification of coherent bichromatic radiation due to its cyclotron parametric interaction with a modulated ensemble of electrons in the absence of partial synchronism of waves and particles. The numerical results agree with the analytical conclusions. We find that under certain conditions, the developing parametric instability is accompanied by “driving” of the wave frequencies to the resonance with the particles, which results in significant “peaking” of the instability.     

Contribution to the theory of parametric generation of cyclotron radiation

A linear theory of the cyclotron parametric instability in systems which are classical analogues of quantum lasers without inversion is developed. The cyclotron interaction of different types of modulated electron beams with a bichromatic field, produced by waves propagating at an angle with respect to a constant magnetic field, is investigated. It is shown that simultaneous amplification of two parametrically coupled modes with different frequencies and positive energy is possible in this system with modulation of the active and reactive components of the susceptibility of an electronic ensemble. The results obtained are important from the standpoint of the general theory of radiation processes in electron beams and plasma and for the advancement of microwave electronics.     

Retrieval of Ozone-Density and Atmospheric-Temperature Profiles using the Spectra of Microwave Absorption in Two Rotational Ozone Lines

We show the possibility of retrieving ozone-density and atmospheric-temperature profiles using the measurements of ozone absorption spectra in two lines with different temperature dependences. Using ozone absorption line measurements with an accuracy that can actually be reached in modern experiments, we demonstrate the possibility of retrieving few points in ozone-temperature and ozone-density profiles with vertical resolution of the order of 6 km, which is usual for microwave sounding.     

Cyclotron mechanism of free-electron lasing without inversion

We consider one of the “paradoxical” effects of the theory of radiation and matter interaction: stimulated emission in the absence of inversion. The theory of simultaneous inversionless emission of two high-frequency waves due to their parametric interaction with ensemble of free electrons in magnetic field is developed. The analytical investigation and numerical simulation of the most interesting scheme of this two-photon interaction are presented. New effects are revealed; namely they are self-induced parametric instability of sufficiently strong waves and enhanced parametric instability in sufficiently dense electron medium.     

Screening of Quantum States of an Optical Field from a Resonant Perturbing Subsystem

Radiophysics and Quantum Electronics - We predict theoretically the effect of screening the quantum states (including entangled ones) of an optical field from interaction with a resonant perturbing...