Mode locking and frequency tuning of a laser diode array in an extended cavity with a photorefractive phase conjugate mirror

Abstract
We demonstrate active mode locking and a tunable narrow spectrum under cw conditions in an extended cavity laser which uses an AlGaAs/GaAs array gain medium and an external feedback from a self-pumped photorefractive phase conjugate mirror. The mirror ensures self-aligned, spatially matched feedback. The mode-locked pulses are 92 ps wide. The tuning, obtained by an intracavity grating, has a range of 70 Å under cw conditions.