Setting up meshes of interferometers - reversed local light interference method

Many interesting linear optical networks, such as lattice filters and some interferometer meshes, are difficult to fabricate precisely and cannot be configured progressively even using recent algorithms. Our approach allows a broad category of optical networks to be set up progressively and automatically, including correcting for fabrication imprecision. We null interference locally in the network based on inputs calculated by considering the network operated in reverse. Calibration is only required for the network inputs, not for individual components (though this method can also calibrate those). We illustrate specific cases of lattice filters and rectangular meshes of interferometers, and we expect the approach can be applied broadly to networks in which the light only propagates forward in the network.