16-channel mode division (de)multiplexer based on densely packed bent waveguide arrays

An ultra-broadband 16-channel mode division (de)multiplexer (MDM) based on densely packed bent waveguide arrays (DPBWAs) is experimentally demonstrated. The scheme is realized by using bent waveguides with different radius. The fabricated device, which consists of a multiplexer, DPBWAs, and a demultiplexer, exhibits insertion losses that are <; 1 dB and crosstalk that is <; -20 dB over an ~ 80 nm wavelength band.