TOPICAL REVIEW: Blue and green semiconductor lasers: a status report
An overview is given of recent laboratory developments in wide-bandgap semiconductor diode lasers. We concentrate on the device science of these blue - green light emitters and outline some of the existing key technical challenges. Following a description of the current device status of the edge-emitting GaN- and ZnSe-based heterojunction lasers, we illustrate the special features of wide-gap semiconductor lasers by focusing on the physics of optical gain and possibilities in short-vertical-cavity structures.