Ultralow bending loss fibers with higher-order mode strippers

Abstract

We propose and demonstrate bend-insensitive fibers equipped with higher-order mode strippers. The mode stripper is realized by filling a section of air holes with epoxy to attenuate any higher-order modes that are excited at fiber junctions and are confined by the air holes surrounding the core. We found that the higher-order modes are well suppressed with 5 cm-long epoxy columns. An ultralow bending loss of 0.025 dB/turn at a bend diameter of 10 mm, together with single-modeness, is experimentally demonstrated in a bend-insensitive fiber with six air holes 16 μm in diameter.