434. D. A. B. Miller, “Establishing optimal wave communication channels automatically,” J. Lightwave Technol. 31, 3987-3994 (2013)
DOI: 10.1109/JLT.2013.2278809 (open access)
We show how multiple optimal orthogonal channels for communicating or interconnecting with waves between two objects can be aligned and optimized automatically using controllable beamsplitters, detectors and simple local feedback loops, without moving parts, without device calibration, without fundamental beam splitting loss, and without calculations. Optical applications include multiple simultaneous orthogonal spatial communication channels in free space or multimode optical fibers, automatically focused power delivery with waves, multiple channel communication through scattering or lossy media, and real-time-optimized focused channels to and from multiple moving objects. The approach physically implements automatic singular value decomposition of the wave coupling between the objects, and is equivalent in its effect to the beam forming in a laser resonator with phase-conjugate mirrors with the additional benefits of allowing multiple orthogonal channels to be formed simultaneously and avoiding the need for any nonlinear optical materials.