A semiconductor material vertical cavity surface emitting laser for
emitting narrow linewidth light comprising a compound semiconductor
material substrate and pairs of semiconductor material layers in a first
mirror structure on the substrate of a first conductivity type each
differing from that other in at least one constituent concentration and
each first mirror pair separated from that one remaining by a first
mirror spacer layer with a graded constituent concentration. An active
region on the first mirror structure has plural quantum well structures
separated by at least one active region spacer layer and there is a
second mirror structure on the active region similar to the first but of
a second conductivity type. A pair of electrical interconnections is
separated by said substrate, said first mirror structure, said active
region and said second mirror structure.