Breakthroughs in Photonics 2013: Passive Mode-Locking of Quantum-Dot Lasers

Most recent achievements in passive mode-locking of quantum-dot lasers, with the main focus on jitter reduction and frequency tuning, are described. Different techniques, leading to record values for integrated jitter of 121 fs and a locking range of 342 MHz, are presented for a 40-GHz laser. Optical feedback is observed to be the method of choice in this field. For the first time, five different optical-feedback regimes are discovered, including the resonant one yielding a radio-frequency linewidth reduction by 99%.