RESONANT-PERIODIC-GAIN DISTRIBUTED-FEEDBACK SURFACE-EMITTING SEMICONDUCTOR LASER

A resonant-periodic-gain distributed-feedback surface-emitting semiconductor laser has a resonator with an axis perpendicular to the plane of the substrate. The resonator comprises a stack of distributed feedback elements, each consisting of a spacer region and a very thin gain element positioned at an antinode of a standing wave inside the resonator at a designed wavelength. Each gain element consists of one or a group of closely spaced quantum-well layers. Each spacer, separating two adjacent gain elements, consists of two intermediate-and low-refractive-index layers, each layer of the spacer having an optical thickness approximately equal to a quarter of the designed wavelength. The refractive index of each of the gain elements is higher than that of the spacer materials. The device can be surrounded by a material of refractive index lower than all materials comprising the device for better confinement of carriers and control of guided modes of radiation. The structure can be directly pumped either optically or with an electron beam. Also, various well known schemes for electrical pumping can be utilized. The devices can be arranged to form one- or two-dimensional arrays.