Abstract

The mode-locking of erbium doped fiber lasers has recently been the subject of active research, and a number of interesting schemes have been reported for the generation of picosecond pulses.^1-2 We describe a new active mode-locking technique for an Er³⁺:fiber ring laser configuration where a traveling wave InGaAsP semiconductor amplifier is used as an intracavity modulator. Our experimental arrangement comprised an angled ridge-waveguide InGaAsP semiconductor amplifier which was coupled via microlensed fiber directional couplers to a length of monomode erbium doped silica fiber as illustrated in Fig. 1. The 5-m length of Er³⁺:fiber was pumped either at 532 nm by a frequency doubled output of a cw mode-locked Nd:YAG laser or by the output of a cw Ti:sapphire laser tuned to 980 nm.

© 1990 Optical Society of America