FEMTOSECOND SELF MODE-LOCKING OF YB-FLUORIDE PHOSPHATE-GLASS LASER

Passive cw mode locking of an ytterbium-doped fluoride phosphate glass laser is demonstrated, for what we believe to be the first time, base d solely on the Kerr effect in the active medium in a resonator viith dispersion compensation. Nearly bandwidth-limited pulses as short as 1 60 fs are generated at approximate to 1040 nm. We obtain average outpu t powers as high as 250 mW at 170-MHz repetition rate with absorbed pu mp power as low as 1.2 W. (C) 1997 Optical Society of America.