Tunable optical waveguide grating arrangement

摘要

A tunable waveguide grating includes a plurality of N waveguides which define N optically transmissive pathways. A plurality of (N-1) electrodes are arranged in the pathways such that the kth pathway contains (k-1) electrodes, where 0<k<N. As a result of this arrangement, an optical signal propagating through the kth pathway will experience a phase shift provided by each of the (k-1) electrodes arranged in that pathway. Consequently, in contrast to prior tunable optical gratings, each electrode may contribute a phase shift to the portions of the signal propagating through several waveguides and hence as the number of waveguides increases no individual electrode is required to produce relatively large phase shifts.