Rewritable Solitons Produced in VCSELs

A team from Institut Non Lineaire de Nice in France, Poltecnico e Università di Bari and Università dell'Insubria, both in Italy, Imedea in Spain and the University of Ulm in Germany has written and erased arrays of stable cavity solitons as 10-µm optical spots in the beams of vertical-cavity surface-emitting lasers (VCSELs). The technique promises a source of pixels for use in all-optical processors.

As reported in the Oct. 17 issue of Nature, the researchers produce the solitons by injecting a writing beam from an edge-emitting laser into a holding beam from a VCSEL. They erase the resulting spots by injecting another pulse that is out of phase. They believe that it should be possible to write several spots simultaneously by introducing appropriate spatial modulations into the holding beam and by improving the homogen-eity of the VCSEL structure.