SIGNAL ROUTING DEVICE

摘要

A signal routing device (10) incorporates a multimode beamsplitter waveguide (20) connected by a set of parallel relay waveguides (22) to a multimode recombiner waveguide (24). Each relay waveguide (22) contains a respective electro-optic phase shifter (36). Sets of input and output waveguides (18, 28) are connected to the beamsplitter and recombiner waveguides (20, 24) respectively. The input and output waveguides (18, 28) are periodically spaced at off-centre positions across the respective multimode waveguide transverse cross-section associated therewith. Radiation in any one of the input waveguides (18) is distributed between the relay waveguides (22) by virtue of modal dispersion in the beamsplitter waveguide (20). The phase shifters (36) apply a set of phase shifts to the distributed radiation. Modal dispersion in the recombiner waveguide (24) results in the phase shifted radiation providing a non-zero input to one or more of the output waveguides (28). Different sets of phase shifts provide for radiation in any one of the input waveguides (18) being transferred selectably to any one or more of the output waveguides (28), as required for selectable signal routing.