Delivery of high power laser beams in a distributed materials processing system

An extensive multi-year experimental study of the delivery of high power laser beams through long step index plastic clad silica fibers was completed. The results show better than expected beam quality delivered at the work piece. An analysis of mode coupling in large step index waveguides was completed to explain the experimental results. One of the primary goals of this research was to develop the capability to predict the diameter of the optics required between the optical fiber and the work piece based on the size of the beam (which may depend on the power level), the size of the fiber, the numerical aperture NA of the fiber, and other parameters. Another goal was to characterize the effectiveness of relatively long delivery fibers in a typical manufacturing environment