Six mode multi-plane light converter for mode-selective spatial multiplexing

We report a six mode spatial multiplexer with high efficiency and high mode selectivity, based on the technique of Multi-Plane Light Conversion (MPLC). Using this mode selective multiplexer, we demonstrate a total insertion loss in a six-mode fiber below 5 dB and a mode-to-mode selectivity greater than 20 dB over a broad wavelength range from 1530 to 1565 nm. Furthermore, this device can address any spatial mode profile of any few-mode fiber with high fidelity. This mode-multiplexer proves to be fully compatible with a wavelength- and space-division multiplexed optical transmission line.