Large-core-area hollow photonic-crystal fibers

We demonstrate hollow‐core photonic‐crystal fibers (PCFs) with a core diameter of 45 μm and a period of the photonic‐crystal cladding of 7 μm. These fibers are shown to allow a waveguide delivery of 4‐mJ 15‐ns pulses of 1.06‐μm radiation of a Q‐switched Nd: YAG laser. Hollow PCFs reported in this work help to bridge the gap between standard, solid‐cladding hollow fibers and hollow PCFs in terms of effective guided‐mode areas, offering attractive solutions for high‐field physics, laser technologies, and ultrafast photonics. (© 2004 by ASTRO, Ltd. Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)