Nonstationary source of resonance radiation at the surface of a stimulated dispersed medium

B. A. Veklenko

Leonid A Bol'shov, V. P. Reshetin

V. N. Abrashin, Pavel A Apanasevich, Anatolii A Afanas'ev +2 more

Vjacheslav B. Gerasimov, E M Zemskov, V. K. Orlov

An analysis is made of nonlinear nonstationary equations describing dynamics of the stimulated Raman scattering in optical resonators excited by external nonmonochromatic radiation. The threshold of the excitation of the stimulated scattering by nonmonochromatic radiation is found and its dependence on the dispersion of the active medium is deduced. Solutions are obtained for steady-state oscillations in a resonator and their characteristics are investigated as a function of the spectrum of the exciting radiation and of the dispersion of the active medium.

V. N. Lugovoǐ, A. L. Dyshko

Stimulated Raman radiation is considered in an optical resonator excited by an external light beam. It is assumed that the resonator is filled with a dispersive (condensed) medium for a length of the medium (along the resonator axis) close to several ‘tunnel’ lengths. A Raman-active medium is assumed to fill part of the resonator length along the resonator axis. Numerical calculations are presented of tunnel locking stimulated Raman radiation components. The shape of light pulses is calculated, and the band of locking Stokes components is derived. The feasibility of generating a light pulse of duration 3 × 10-14 −4 × 10-15 s in a frequency region close to the point ∂2 n eff / ∂ω2 = 0, located usually in the infrared spectral region (n eff is the effective refractive index of the substance inside the resonator) is discussed. Also discussed is the feasibility of correcting the refractive index dispersion and generating femtosecond light pulses in the visible spectral region.

Sergei N Bagaev, V. S. Egorov, Igor B. Mekhov +4 more

An experimental and theoretical study of the two-wave interaction (of a probe wave and a pumping wave) of wide-band multimode laser pulses with an optically dense extended resonant medium (metastable neon atoms in a positive glow-discharge column) is presented. Depending on the pumping power and characteristics of the medium, various regimes of interaction between the field and the matter, leading to qualitatively different types of amplification spectra, are realized: a cooperative interaction regime at low pumping powers corresponds to amplification spectra consisting of two peaks, which lie on both sides of the absorption line; in the regime of nonstationary Rabi oscillations (Rabi flopping), the amplification appears in the form of an isolated peak at a frequency close to the resonance in the substance; under certain interaction conditions, a dispersive shape of amplification spectra is observed. A significant gain in the probe field (by several times at a length of 10 cm) is obtained as a result of a nonstationary population inversion upon rotation of the Bloch vector of the resonant medium under the action of a strong pumping field in the course of propagation of the two waves.