Uncooled, isolator-free 10Gb/s transmission over 20 km of standard fibre at 1.55μ with directly modulated quantum dot DFB laser

We study modulation properties of state-of-the-art quantum dot lasers and compare them with state-of-the-art Al-based quantum well lasers. In particular, we demonstrate uncooled transmission over 20 km at 10 Gbit/s, limited by a large adiabatic chirp.