Ring laser with an active amplitude isolator

Theoretical and experimental studies of the characteristics of an Nd:glass traveling-wave ring laser with an active amplitude isolator are presented. The threshold gain, the intensity ratio of counterpropagating waves, and the dependence of these characteristics on the parameters of the resonator and the active medium are determined. It is shown that the contribution of additional active material between the two mirrors of the active isolator is insignificant. However, the presence of this additional active material significantly reduces the time of the establishment of a single-mode lasing regime and facilitates the achievement of the maximum of coherent radiated power at the maximum value of the suppression coefficient for counterpropagating waves.