Edge emitting mode-locked quantum dot lasers

Edge-emitting mode-locked quantum-dot (QD) lasers are compact, highly efficient sources for the generation of picosecond and femtosecond pulses and/or broad frequency combs. They provide direct electrical control footprints down to few millimeters. Their gain bandwidths (up 50 nm ground state transitions as discussed below, with potential increase more than >200 by overlapping excited band transitions) allow wavelength-tuning pico- laser over a wavelength range. In last two decades, QD have become promising tools low-power applications in ultrafast photonics. this article, we review development state-of-the-art edge-emitting lasers. We start brief introduction on active media their uses lasers, amplifiers, saturable absorbers. further discuss basic principles mode-locking including theory nonlinear phenomena waveguides, carrier dynamics, methods. Different types systems, such monolithic one- two-section devices, external-cavity setups, two-wavelength operation, master-oscillator power-amplifier compared. After presenting recent trends results field briefly application areas.