Possibilities and limitations of space-variant holographic optical elements for switching networks and general interconnects

Space-variant optical elements are necessary for realizing optical interconnects of arbitrary design. For such applications, planar holographic optical elements offer the highest degree of flexibility and ease of production; however their diffraction-based operation gives rise to chromatic aberrations. Here estimates for the number of independent space-variant interconnects, their spatial tolerances, and their wavelength stability are considered for close-cascade, and related, geometries.