Passive coupled-cavity mode-locked color-center lasers

Stable, self-starting operation of a coupled-cavity mode-locked KCl:T1(0)(1) color-center laser has been achieved by incorporating a semiconductor diode optical amplifier into the control cavity. By adjustment of the amplifier drive current, nonlinearity in the regimes of either saturable gain or saturable absorption has been exploited to generate subpicosecond pulses. Under conditions of saturable gain, pulse durations as short as 280 fs were obtained. Self-starting has also been demonstrated for a coupled-cavity mode-locked NaCl:OH(-) color-center laser by using the same technique.