All-Glass Large-Core Leakage Channel Fibers

Leakage channel fibers (LCFs) have demonstrated their ability to significantly extend the effective mode area of a fundamental mode while maintaining robust single-mode operation. These fibers are designed to have strong built-in mode filtering that effectively suppresses the propagation of all higher order modes while keeping fundamental-mode loss to a minimum, and, therefore, effectively extending the regime of single-mode operation. Recently, all-glass LCFs have been demonstrated as a significant improvement over designs with air holes. These all-glass LCFs can not only be manufactured with much improved consistence and uniformity, but can also be handled and used as conventional fibers. More importantly, mode distortions from collapse of air holes in photonic crystal fibers during splicing and other endface treatments are largely eliminated. We will review some of the recent progress in this area.