Multiring large-mode-area delivery fiber for high power

The study presents a novel design of multiring delivery fiber with large mode area for high power. Using a FiberCAD method, we investigated a fiber whose core is surrounded by alternative low-and high-index rings. Based on our calculation, the effective area is 400 mu m(2) at 1.08 mu m, larger than the similar to 280 mu m2 of conventional step-index fiber (20/400). The macrobending loss at 1.08 mu m is estimated to be 1 x 10(-3) dB/m, approximately one-third that of conventional step-index fiber (20/400). The single-mode operation can be achieved by the macrobending loss contrast between the fundamental mode (<1 dB/m) and high-order mode (>100 dB/m). The results indicate that multiring delivery fiber fabricated by modified chemical vapor deposition process is a promising candidate for high-power transmission. (C) 2013 Optical Society of America