Beam shaping of high-power diode lasers

Summary form only given. The main advantages of diode lasers are their small size, long life time, high efficiency and frequency controllability. At the moment the obtainable output power from a typical 200 /spl mu/m emitter is about 2 W. Typical diode laser bars consists of about 20 emitters and delivers about 40 W. The beam quality after fast axis collimation is about M/sup 2/=3 along the fast axis and 1500 along the slow axis and is extremely asymmetrical. For enabling efficient fiber coupling of diode laser radiation different beam shaping techniques have been developed. The common feature of all beam shaping techniques is to group the beam into subbeams along the slow direction and to rearrange them along the fast axis. The beam quality along both axes can be matched by suitable selection of the number of subbeams.