US Patent 7723640 Optical horned lightpipe or lightguide

A laser welding apparatus having a laser source outputting a laser beam and a light transmitting device being positioned downstream from the laser source. The light transmitting device transmits the laser beam therethrough. The laser beam exiting the light transmitting device has at least a zero order light lobe and a first order light lobe, wherein the zero order light lobe and the first order light lobe together defining an initial beam width. An optical device positioned downstream from the light transmitting device converges the first order light lobe with the zero order light lobe to define a final beam width that is narrower than the initial beam width.