Interaction of counterpropagating waves in a Nd : YVO4 ring laser

We have experimentally studied the stationary regime of bidirectional lasing and self-modulation regimes in a Nd : YVO₄ solid-state ring laser (SSRL) in the presence of phase nonreciprocity of the ring cavity. It is found that the emission spectrum in the regime of frequency matching of counterpropagating waves is much narrower than in a Nd : YAG SSRL. When the phase nonreciprocity increases in the matching regime, one of the counterpropagating waves is suppressed, and this regime does not switch to the beat regime.