Theory of the mode-locked, internally frequency-doubled laser

An AM mode-locked laser with a frequency doubler internal to the laser cavity is analyzed. Mathematical expressions are derived for laser pulsewidth, saturated gain, and second-harmonic output power. It is shown that the maximum second-harmonic power output available from the mode-locked laser is a factor of \sqrt{2} less than that available from an identical free-running laser. Numerical examples are given for an Nd:YAG laser with a Ba 2 NaNb 5 O 15 internal frequency doubler.