Active Lattice Filter with nanophotonic FTIR-couplers for integrated photonic channelizer

A 2D Active Lattice Filter ALF combining a Manhattan grid of waveguide gain segments with nanophotonic couplers at the waveguide intersections is presented. The particular application reported herein is a basic channelizer. The resulting structure is readily described, designed, and analyzed in Z-transform space. Critical to the implementation of the 2D ALF circuit is a highly efficient small footprint coupler based on frustrated total internal reflection (FTIR).