An optical beam combiner is provided, which allows efficient collection of
light for various applications: non-line of sight and free space optical
communications, remote sensing, optical imaging and others. A multitude
of optical beam portions is captured by a space diversity receiver that
includes an optical beam combiner, which has a tree-like topology with
interconnected waveguides, electro-optic phase shifters, and directional
couplers. For each of the beam portions the phase of the phase shifter
and the coupling ratio of coupler in the optical beam combiner are tuned
sequentially to maximize the final output power in the final optical
waveguide. A portion of the final output beam is used for the power
detection and forming a feedback signal for the phases and coupling
ratios adjustment. The data or information is recovered from the received
final optical beam using coherent detection.