Asymmetric adiabatic multiprong for mode-multiplexed systems

The adiabatic, asymmetric multiprong splitter is the basic multiplexing/demultiplexing device in a mode multiplexed system. Devices with up to four modal channels are analysed with the beam propagation method, which shows, theoretically, that such devices can selectively drive/sense the individual modes of up to a four-moded waveguide with extinction ratios of greater than -25dB and negligible excess loss. Typical device lengths are 10, 15 and 50mm for two-, three- and four-channel splitters, respectively.