A planar optical router consisting of two stages performing stationary imaging has advantages of reduced size, increased number of channels and reduced crosstalk. In one embodiment, each stage of the router includes a waveguide grating, and the router produces several sets of interleaved images, with the property that different sets are characterized by different diffraction orders of the two gratings. The new arrangement substantially increases the number of output waveguides, as compared to previous arrangements using only one set of images, characterized by the same order of the output stage. Moreover, since adjacent sets are characterized by different orders, crosstalk is substantially reduced. In a second embodiment, the number of output waveguides is further increased by including two gratings in the second stage.