The traffic of data produced by local area networks, storage area networks, access networks and mobile infrastructure networks is strongly increasing every year. As a consequence the serial bit rates of the transmitters have been continuously upgraded from 1 Gbit/s to 10 Gbit/s.

It is expected that the demand for data rate driven by the next (4th) generation of mobile devices and the deployment of IPTV or video-on-demand (VoD) will force the network operators to upgrade their transmission capabilities from today's 2.5 Gbit/s and 10 Gbit/s to 40 Gbit/s by 2008 and to 100 Gbit/s by 2010. In order to meet these requirements, a new generation of telecommunication lasers must be developed.

Two most important issues that need to be addressed are the decreased cost of a single device and high modulation speed of lasers operating at proper wavelengths. The DeLight project is devoted towards finding the technological solutions that will satisfy both conditions, mainly via the development of improved surface structuring, but also through the advances in the lasers active regions.