Harmonic mode-locking in quantum dot lasers with tunnel-coupled waveguides

Passive mode-locking has been studied in the lasers with tunnel-coupled waveguides with the active region based on InAs/InGaAs quantum dots emitting in the range of 1.3–1.31 μm. Specific optical mode formation in this composite waveguide reduces the output beam divergence and raises the temperature stability of the lasing wavelength. The reduced optical confinement factor facilitates obtaining passive modelocking regimes. High response rate of the saturable absorber associated with the carrier escape time shorter than 20 ps allows generating a third harmonic with the frequency as high as 46.1 GHz.