Amplitude noise reduction of a coupled-cavity mode-locked NaCl:OH- color-center laser by active synchronization.

Stable noise-free operation of a coupled-cavity mode-locked NaCl:OH− color-center laser was obtained by synchronizing it to the mode-locked Nd:YAG pump laser. This stabilization technique, based on active cavity-length control of the color-center laser, eliminated the amplitude modulation of the output power arising from the beating of the pump laser pulse train with the color-center laser pulse train.