Abstract

The manufacture of vertical-cavity surface-emitting semiconductor lasers (VCSELs) lasing around 1550 μm, where the silica optical libers exhibit a minimum in the optical losses, is under active research [1]. VCSELs operating at that wavelength are expected to offer a good performance as optical emitters in optical communication systems working at Gbit/s rates. Several advantages become evident. Because of their cylindrical geometry, good matching with standard monomode optical fibers has been demonstrated, with power losses lower than 10%. The surface emission characteristics of VCSELs allow integrability in two-dimensional laser arrays. Investigations of the performance of VCSELs under current modulation or gain-switching operation are important to characterize possible improvements with respect to the widely used edge-emitting lasers (EELs). One of the drawbacks of EELs is the natural tendency to lase in several longitudinal modes under large signal modulation, even when the side mode suppression ratio (SMSR) during steady-state operation is large [2]. Although transient multimode operation can be efficiently suppressed by using DFB structures, any damage in the AR-coatings on the laser facets can trigger the appearance of side modes.

© 1996 Optical Society of America