Surface-emitting lasers with periodic gain and a parallel driven nipi

Abstract

A surface-normal cavity, AlGaAs, Distributed-Bragg Reflector laser. The laser is constructed on a GaAs substrate. There is a nipinipi . . . gain-producing active section comprised of a plurality of gain-producing i-segments disposed at periodic intervals with respect to the wavelength of an intended operating frequency of the laser is stacked vertically with respect to the surface of the substrate. A pair of Distributed-Bragg-Reflector stacks are disposed at the respective ends of the nipinipi . . . active section. A pair of electrodes are formed on either side of and operably connected to the nipinipi . . . active section in electrical contact therewith for applying a driving current to the nipinipi . . . active section in parallel. In one embodiment, the nipinipi . . . active section has interfaces between p+ and n+ sections thereof positioned at standing wave maxima of the intended operating frequency of the laser. In another, the nipinipi . . . active section has interfaces between p+ and n+ sections thereof displaced from standing wave maxima of the intended operating frequency of the laser an amount which will allow the impedance discontinuity of the active segment to result in more in-phase reflection components whereby the gain-producing active section acts as a mirror and the net effective reflectivity of the laser is increased.