Optimization of intracavity Q-switched laser frequency doubling

The optimization theory for intracavity frequency-doubled Q-switched lasers is discussed. Nonlinear loss effects caused by the frequency doubler were introduced into the rate equations. The harmonic pulse characteristics such as peak power, pulse energy, pulsewidth were studied. Lagrange multiplier technique was adopted to maximize the peak power of the second-harmonic pulse for a given pumping level. It was found that the optimal frequency-doubling factor is constant and equals 1. Design curves for the laser characteristics parameter were established. The curves and expressions presented help in designing an optimal Q-switched intracavity frequency-doubled miniature laser and predict the pulse characteristics.