Low-voltage device for passive mode locking of pulsed infrared lasers

A reliable mode-locking device which can be used to generate short CO$_2$ laser pulses has been developed and investigated. The device uses $p$-type germanium filters cooled to 78$^\circ$K, having a low threshold (10–15 MW/cm$^3$) and a short bleaching time ($\lesssim$ 0.1 nsec). As a whole, the system can withstand more than 10$^5$ lasing cycles without appreciable damage to the antireflection coatings and laser elements.