No abstract

The continuously tunable twin-guide (TTG) distributed feedback (DFB) laser has been fabricated on semi-insulating substrate for the first time. A new contacting scheme is applied with all three contacts on top of the laser chip. The fabrication requires only four metalorganic vapour phase epitaxy (MOVPE) stages, i.e. only as many as that of simple TTG-DFB lasers on p-type substrate. An electronic tuning range of 1.2 nm has been achieved despite a high series resistance, which will be considerably reduced by optimising the structure. The fabrication on semi-insulating substrates makes the TTG-DFB laser suitable for integration in a heterodyne receiver chip.