High brightness semiconductor lasers by inhomogeneous pumping

Summary form only given. High power semiconductor lasers have applications in spectroscopy, telecommunications, manufacturing and materials processing medicine, free space communication or energy transfer. Powers of /spl sim/1 W or more require large apertures /spl sim/100 pm which lead to high order transverse modes, filamentation and spatio-temporal instabilities, all of which degrade spatial coherence and therefore brightness. In this paper we describe recent theoretical and experimental research to develop laser structures and resonators to suppress filamentation and high order transverse mode oscillation. We have fabricated and analysed broad area lasers, unstable resonators, and flared lasers.