A new concept for a high brilliance high power diode laser

The main problem of high power diode lasers is the incoherent combination of many laser diodes, resulting in a very poor beam quality. This incoherent beam combination can be avoided by time multiplexing, i.e by laser diodes emitting high peak power laser pulses, operated such that one diode after another emits a pulse and a steering of the pulses with a fast scanner on a common optical path. The resulting pulse train has nearly the same beam quality as a laser beam produced by one laser and can also be treated like that. Every kind of beam deflector can in principle perform the second task. Since the duration of diode laser pulses of reasonable power is in the order of 100 ns only electro-optical methods are fast enough. We propose an inverse digital beam deflector. Assume a polarized laser beam passing a Pockel's cell and a birefringent crystal. Which way is taken by the beam depends whether the Pockel's cell has turned the polarization of the beam by 90/spl deg/ or not. Hence the beam can take two different ways. This can be used in the reversed way as time/polarization multiplexing to combine laser pulses from different sources emitted at different times.