Harmonic Mode-Locking of a Quantum-Dot Laser Diode

A detailed study of harmonic mode-locking in a quantum-dot laser diode is presented. Mode-locking of the 1<sup>st</sup>, 2<sup>nd</sup>, 3<sup>rd</sup> and 6<sup>th</sup> harmonics are demonstrated, corresponding to repetition rates ranging from 39 GHz to 238 GHz