E G Lariontsev

Switching of synchronized chaotic oscillations in a modulated solid-state ring laser

We study synchronization in chaotic oscillations of counterpropagating waves in a solid-state ring laser with a periodically modulated pump. The new phenomenon of spontaneous switching of in-phase- and anti-phase chaotic synchronization has been discovered in a numerical experiment.

Relaxation oscillations in a self-modulated solid-state ring laser

Abstract Noise driven relaxation oscillations of a solid-state ring laser undergoing stable dynamical periodic pulsation are investigated for the first time. Formulas for the relaxation oscillation frequencies in the presence of frequency nonreciprocity are derived. It is shown that, in the case of symmetric backscattering, the self-modulation regime is characterized by damped relaxation oscillations. The conditions are found for which the relaxation oscillation frequencies are nondegenerate over the whole range in which the frequency nonreciprocity can be varied. The dependence of the relaxation oscillation frequencies on parameters of the sinusoidally alternating bidirectional ring laser is substantially different from the corresponding dependence for unidirectional operation.

Chaotic synchronization and evolution of optical phase in a bidirectional solid-state ring laser

We present results on experimental and theoretical studies of chaos in a solid-state ring laser with periodic pump modulation. We show that the synchronized chaos in the counter-propagating waves is observed for the values of pump modulation frequency fp satisfying the inequality f1 < fp < f2. The boundaries of this region, f1 and f2, depend on the pump-modulation depth. Inside the region of synchronized chaos we study not only dynamics of amplitudes of the counter-propagating waves but also the optical phases of them by mixing the fields of the counter-propagating waves and recording the intensity of the mixed signal. We demonstrate experimentally that in the regime of synchronized chaos the regular phase jumps appear during intervals between adjacent chaotic pulses. We improve the standard semi-classical model of a SSRL and consider an effect of spontaneous emission noise on the temporal evolution of intensities and phase dynamics in the regime of synchronized chaos. It is shown that at the parameters of the experimentally studied laser the noise strongly affects the temporal dependence of amplitudes of the counter-propagating waves.

Frequency response of a gas ring laser with a variable-sign frequency bias in the case of frequency nonreciprocity comparable with the bias amplitude

The dependence of the beat frequency of counterpropagating waves on the rotation rate is studied theoretically and experimentally in a gas ring laser (GRL) with a Zeeman effect-based, variable-sign frequency bias. Use is made of magneto-optical biases of two types, namely, a rectangular (meander) bias and a combined bias consisting of fast and slow meanders. At high rotation rates, when the frequency nonreciprocity determined by the rotation rate is close in magnitude to the amplitude of the variable-sign frequency bias, the dynamic locking bands take maximum values and there arise the most extensive deviations of the frequency response from the ideal response. Comparison of experimental and theoretical results for the widths of dynamic bands that appear in this region of the measured rotation rates shows good agreement between theory and experiment. The results suggest that the frequency response of a GRL in this region can be described by one differential equation for the phase difference of counterpropagating waves.

Analysis of mode locking in a laser with a traveling-acoustic-wave modulator

A theoretical analysis is made of active mode locking in a solid-state laser with an acoustooptic modulator based on traveling acoustic waves. It is postulated that the acoustooptic modulator is placed in a V-shaped resonator so that diffraction feedback is established in the modulator. It is found that the transmission coefficient of the acoustooptic modulator is a function of time. The mode locking achieved in a V-shaped resonator is equivalent to that observed in lasers with intracavity frequency modulation of the radiation. An investigation is made of the stability of mode locking in a resonator with a traveling-acoustic-wave acoustooptic modulator.

Solid-state ring laser with self-pumping waves operating under active mode-locking conditions

Theoretical and experimental investigations were made of the amplitude and frequency characteristics of a rotating solid-state (YAG:Nd3+) ring laser with self-pumping waves. The self-pumping wave method produced effectively the competition between opposite waves and made it possible to achieve a stable beat regime in this laser. The use of self-pumping waves in a solid-state laser under active mode-locking conditions was found to have a number of advantages over free running. Various methods for generation of self-pumping waves under active mode-locking conditions were proposed and tested experimentally: this demonstrated ways of improving considerably the amplitude and frequency characteristics of the rotating solid-state laser.