Stabilization of the beat regime and alternating-sign optical nonreciprocity in the case of time-dependent self-diffraction of self-pumping waves in the active medium of a ring solid state laser
A new method is proposed for controlling the amplitude-frequency characteristics of a rotating ring solid-state laser with a homogeneously broadened gain profile of the active medium operating under mode-locked conditions. This method involves the use of ultrashort self-pumping pulses generated by a time-dependent diffraction acoustooptic feedback loop and characterized by a Doppler-modulated optical frequency. It was found experimentally that time-dependent self-diffraction of the main and self-pumping ultrashort pulses by interference population-inversion gratings induced in the active medium gives rise to a new nonreciprocal optical effect (self-induced alternating-sign difference between the frequencies of the counterpropagating waves) and stabilizes the beat regime in such a ring laser.