Synchronization of lasers with intracavity second harmonic generation

A theoretical analysis is made of the characteristics of the operation of two coupled solid-state lasers under conditions of intracavity second harmonic generation. The requirements in respect of the initial phase detuning and the initial frequency detuning of the resonators for the first and second harmonics are formulated in discussing the steady-state problem. It is shown that depending on the nonlinear conversion efficiency, the locking band may differ considerably (by a factor of 1.5–2) from the case when nonlinear conversion does not occur in the lasers. The dependences of the degree of the temporal synchronization on the coupling coefficient are obtained for single-pulse lasers in a wide range of values of the nonlinear conversion coefficient, initial detunings, and excitation power. The results are given of an investigation of the phase-frequency synchronization of pulsed lasers. The dependences of the degree of frequency synchronization on the conversion coefficient, frequency detuning, and coupling coefficient are obtained.