Mode energy transfer in intracavity-frequency-doubled solid-state lasers

Certain solid-state lasers incorporating intracavity frequency doubling have traditionally suffered the major drawbacks of reduced overall second-harmonic conversion efficiency and deep modulation of the frequency-doubled output. These problems are associated with the natural tendency for the laser to operate in multiple-longitudinal modes. The authors have observed, however, smooth energy transfer between longitudinal modes in such a laser, and have modeled this transfer using a mode-pool formalism. The possible explanations for such observations and the impact on system performance are discussed