Multiport N x N multimode air-clad holey fiber coupler for high-power combiner and splitter

Opt Lett. 2005 Oct 15;30(20):2697-9. doi: 10.1364/ol.30.002697.

Abstract

We report 2 x 2 and 4 x 4 multimode air-clad holey fiber couplers fabricated by a novel fusion and tapering technique. The devices showed excellent port-to-port coupling uniformity over a wide spectral range of 800-1650 nm. The 4 x 4 coupler showed a low insertion loss of 9.9 dB and excess loss of 3.9 dB at 1310 nm. Because of its unique air cladding and the high numerical aperture of the holey fiber structure, the device showed strong potential in high-power applications.