Mode-division multiplexing using femtosecond laser written 3-dimensional tapered couplers

摘要

We present ultra-broadband two- and three-mode multiplexers/de-multiplexers for few-mode optical fibres based on femtosecond laser written 3-dimensional tapered velocity couplers. The devices exhibit >20 dB coupling (LP01 to LP11) over a bandwidth of 400 nm.