Laser Beam Combining:
Fundamentals and Current Trends

Prof. James Leger
Electrical and Computer Engineering
University of Minnesota

All laser types are ultimately limited in overall brightness by one or more physical phenomena. Because of this, increasing the brightness of a single laser beyond these limits is exceedingly difficult. For example, recent progress in fiber laser design has produced sources with output powers in excess of 10 KWatts. However, beyond this point, fiber lasers appear to be severely compromised by nonlinear effects such as stimulated Brillouin scattering in the gain medium.  An alternative path to increased brightness is provided by special purpose optics that combines the power of many disparate lasers into a single coherent beam. This colloquium presentation, abstracted from an invited tutorial presented at the 2010 Conference on Lasers and Electrooptic, reviews the fundamental physics of beam combining along with several of the most recent developments in the field.