Leakage channel optical fibers with large effective

Leakage channel fibers, where few air holes form a core, can be precisely engineered to create large leakage loss for higher-order modes, while maintaining negligible transmission loss for the fundamental mode. This unique property can be used for designing optical fibers with large effective area, which supports robust fundamental mode propagation. The large air holes in the design also enable the optical fibers to be bend resistant. The principles of design and operation regime are outlined, demonstrating the potential of this approach for optical fibers that propagate a fundamental mode in core diameter exceeding 100 mu m. Performance of a fabricated passive leakage channel fiber, an ytterbium-doped double-clad leakage channel fiber, and an ytterbium-doped polarization-maintaining double-clad leakage channel fiber are also discussed. (c) 2007 Optical Society of America.