A new optical switch design is reported consisting of two sets of parallel channel waveguides
intersecting at right angles. Arrays based on Ti:LiNbO3 technology, with waveguide intersections iron
doped to provide photorefractive sensitivity, have been fabricated. Interfering guided beams are used to
write index gratings at the waveguide intersections, which in turn diffract a portion of an incident signal
beam into the crossing waveguide. Arrays ranging from 15 x 15 up to 50 x 50 waveguides are
constructed in an active area of 5 mm square. Diffraction efficiency and writing time measurements are
reported along with a brief theoretical analysis. A proposal for a practical architecture offering
nondestructive readout is described.