High efficiency optical logic devices and interconnect elements are required for digital optical experiments. Nonlinear interference filters, capable of acting as optical gates, have been demonstrated to switch with ~2 mW input power and ~50 us recovery time. Switch contrast of 20:1 has been achieved with multicavity designs. Switch energies for micrometre-dimension transversely isolated pixels of 90% diffraction efficiencies have been fabricated in dichromated gelatin and assessed.