Generation of femtosecond optical pulses by a laser with combined mode locking and new saturable absorbers

An experimental investigation was made of combined mode locking and two new dyes 3492-u and 3490-u. In a linear single-jet rhodamine 6G laser the dye 3490-u yielded stable mode locking over the complete tuning range (576–615 nm). The pulse duration varied between 180 and 250 fs in the tuning range and the lasing efficiency was up to 17%. The lasing characteristics were maintained during operation of the active mixture for a month.