Mode locking of an external cavity asymmetric quantum-well GaAs/AlGaAs semiconductor laser

A theoretical model of the optical gain in asymmetric GaAs/AlGaAs quantum-well lasers is developed. It is demonstrated that the emission spectrum of asymmetric GaAs/AlGaAs quantum-well lasers is much broader than that of standard quantum-well lasers. The experimental samples of such lasers and superluminescent diodes with the emission bandwidth exceeding 50 nm are fabricated. Wavelength tunable ultrashort pulses with duration of 1–2 ps at repetition rates of 0.4–1 GHz are obtained by active mode locking of an external cavity laser.