Patent ID: 7035500

Claim:
A device for space selective switching of an optical signal from an input access waveguide to a first selected output access waveguide, said device comprising: a multi-mode interference (MMI) waveguide having at a first side a number, N, of accesses for connection of access waveguides, said MMI waveguide having a length, in light propagating direction, so that an image at an I:th access waveguide will produce N self-images at a second side opposite to said first side, where N is an integer greater than 1, reflective means located in said MMI waveguide close to said second side, arranged to reflect said N self-images towards said first side of said MMI waveguide, and means comprising N individual phase shifters arranged in line perpendicular to the propagation directIon of incident light at said second side, for adjusting the phase of each of said self-images to create a single self-image at said selected output access waveguide, wherein said reflective means is arranged on a surface, facing the light propagating direction, of each of said phase shifters, and wherein each of said phase shifters comprises means for adjusting its position in a direction parallel to the light propagation direction in said MMI waveguide.