ULTRASHORT PULSES IN DIFFRACTION-LIMITED BEAM FROM DIODE-LASER ARRAYS WITH EXTERNAL-CAVITY

Picosecond pulses are generated in a diffraction-limited beam from passive (hybrid) modelocked conventional (lambda = 0.8 mum) diode laser arrays in an external cavity. The emitted energy (10-20 pJ) is almost one order of magnitude higher than that obtained from single stripe quantum well lasers at similar pulse durations. The shortest pulses (approximately 3 ps, 3 nm spectral width) are obtained strong saturable absorbers and 1% antireflection coatings. Correspondingly, external cavities with relatively low angular selectivity can be used in these conditions.