Proton bombardment technique for high speed (>1 Gbit/s) 4 section bistable DBR wavelength converter

Wavelength conversion is a key function for optical switching using wavelength routing. Among the different solutions (gain saturation in semi-conductor amplifiers or in DBR lasers) bistable lasers based on saturable absorption are attractive with their signal reshaping capability but they have been limited in speed by the carrier lifetime of the absorption section. To overcome this limitation, we have optimised a proton bombardment technique of the saturable absorber and applied it to the realisation of (4 section) high speed bistable DBR lasers. Wavelength conversion is thus demonstrated at 1 Gbit/s together with Extinction Ratio regeneration