Method of and means for controlling the electromagnetic output power of

Abstract

The present invention relates to a separate confinement heterostructure laser, and in particular to a stripe geometry, ridge waveguide geometry, having an active layer positioned between a pair of n-type and p-type emitter layers which inject charge carriers under the ridge guide into the active layer. A pair of ohmic contacts are used to inject one type of charge carrier into at least one emitter layer outside the ridge area. When a signal is applied to the pumping contacts (p- and n-type) in forward bias and an intermittent electric field is applied to the ohmic side contacts, the flow of current injected by the side contacts controls the densities of carriers injected by the pumping contacts, thereby controlling spatially and temporally the optical gain and optical confinement factor. In another embodiment, a stripe geometry, ridge waveguide heterostructure laser is disclosed having pumping contacts under the ridge guide to an active layer between two emitter layers with a portion coextending transversely through the ridge and another portion extending laterally outside the ridge. A pair of electro-optic dielectric layers are positioned on the portion of one emitter layer extending outside the ridge. An electric field is applied to the emitter layers under the ridge contact to inject two types of charge carriers into the active layer, and an intermittent electric field is applied across the dielectric layer outside the ridge guide to modulate the refractive index, thereby controlling the optical mode shape. By synchronously applying signals to the pumping contacts and to the side contacts, modulation above 50 MHz can be attained and picosecond pulses can be generated in the devices of both embodiments, thereby reducing chirp and relaxation oscillations.