We demonstrate a widely tunable passively mode-locked fiber laser oper
ating at a fundamental frequency of 80 MHz with an output power of 90
mW. The laser is capable of generating 5-ps pulses in the region 1010-
1064 nm. A strong mode-locking mechanism promoted by frequency-shifted
feedback allows us to operate in simultaneous Q-switched and mode-loc
ked regimes and to obtain peak power in excess of 1.2 kW. (C) 1998 Opt
ical Society of America.