Patent ID: 8494018

Claim:
A laser system having separately electrically operable cavities for emitting modulated narrow linewidth light, said system comprising: a compound semiconductor material substrate; at least two first-mirror pairs of semiconductor material layers in a first mirror structure on said substrate of a first conductivity type; a first active region on said first mirror structure with plural quantum well structures; at least twenty second-mirror pairs of semiconductor material layers in a second mirror structure on said first active region of a second conductivity type; a second active region on said second mirror structure with plural quantum well structures; at least two third-mirror pairs of semiconductor material layers in a third mirror structure on said second active region of said first conductivity type, wherein reflectivities of the first mirror structure and the third mirror structure are substantially equal; an intermediate electrical interconnection at said second mirror structure; and a pair of electrical interconnections separated by said substrate, said first mirror structure, said first active region, said second mirror structure, said second active region, and said third mirror structure.