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 .