High Power Optical Fibers

Photonic bandgap fibers are described that can be solid across the core and clad and have a large core diameter with little loss in the fundamental mode. In addition, the mode loss of the higher order modes can be much greater than that of the fundamental mode, providing high power fibers with high effective mode area. Excellent single mode output can be obtained from the fibers in length scale close to what is required for fiber laser and amplifiers