An optical switching system is described. The system includes a plurality of interconnected wavelength selective switching units. Each of the wavelength selective switching units is associated with one or more server racks. The interconnected wavelength selective switching units are arranged into a fixed structure high-dimensional interconnect architecture comprising a plurality of fixed and structured optical links. The optical links are arranged in a k-ary n-cube, ring, mesh, torus, direct binary n-cube, indirect binary n-cube, Omega network or hypercube architecture.