Low-Loss Bloch Waves in Open Structures and Highly Compact, Efficient Si Waveguide-Crossing Arrays

Low-loss, compact, broadband silicon-waveguide crossing arrays and active structures are proposed based on periodicity-matched multimode focusing. Simulations show loss of 0.045dB/crossing and ≫200nm bandwidth in a typical example. Correspondence to low-loss, structure-matched Bloch-waves is demonstrated.