The invention is an improved planar waveguide device comprising a plurality of optical waveguides and one or more crossover regions where two waveguides intersect at an angle. In accordance with the invention, loss and crosstalk produced by the crossover are reduced by segmenting the waveguides across the region of intersection. Advantageously, the segments are also enlarged in width (as compared to transmission regions of the waveguide remote from the crossover) and offset with respect to the longitudinal axis of the waveguide. In regions where the segments intersect, they merge into a complex segment having a shape corresponding to the periphery of the segment intersection.