Abstract: In an optoelectronic device, light is restrained from propagating in one or both confining layers on either side of an active layer by forming one or more photonabsorbing barriers in one, or both, confining layers. A photon absorbing barrier can be formed by proton bombardment of a confining layer, by producing a protrusion from the substrate into the adjacent confining layer, or by producing a protrusion from a capping layer into the other confining layer, or by combinations of these. Spaced apart barriers can define a device, or sections of a multi-sectioned device, for example a monolithic light emitting diode and modulator.

Abstract: In an optoelectronic device, light is restrained from propagating in one or both confining layers on either side of an active layer by forming one or more photon absorbing barriers in one, or both, confining layers. A photon absorbing barrier can be formed by proton bombardment of a confining layer, by producing a protrusion from the substrate into the adjacent confining layer, or by producing a protrusion from a capping layer into the other confining layer, or by combinations of these. Spaced apart barriers can define a device, or sections of a multi-sectioned device, for example a monolithic light emitting diode and modulator.

Abstract: A photodiode detector comprises a substrate on which a plurality of detector sections are formed, in series. Reverse bias is applied to the separate sections, the bias more negative for each section from the input end. The absorption bandwidth for each section can vary and the bandwidth of a section can be variable.