Recent developments in the area of vertical cavity surface emitting lasers

Vertical Cavity Surface Emitting Lasers (VCSELs) show potential for use as low cost sources for optical communication. The structure is compatible wit h fabrication of 2 dimensional arrays, as no cleaved facets are needed for mirror function. In addition, the intrinsic single mode operation of the de vices due to the short cavity leads to very high fabrication yield. Very fa st progress has been achieved in the recent years for 0.85 - 0.98 mu m VCSE Ls fabrication. VCSEL arrays are therefore used in parallel optical interco nnection systems; these systems are presently available on the public marke t. Bit rate as well as transmission length are however limited mainly by th e multimode fiber used at this wavelength. In order to upgrade such systems beyond Gbit/s operation over several kilometres, important efforts are dev oted to the development of 1.3 - 1.55 mu m VCSELs today. Starting with a si mple test structure for the optimisation of optical (mirror), thermal (mate rial) and electrical properties, we have proposed and demonstrated an origi nal structure emitting at 1.3 mu m. CW operation is observed up to -15 degr ees C. Characterisation of the devices are detailed as well as the way to i ncrease their performances.