Patent ID: 7949262

Claim:
An optical device for an optical beam receiving, comprising: 2 M input waveguides, where M is an integer ≧1, receiving different spatial portions of the optical beam propagating in free space; the waveguides forming an array positioned perpendicular to the optical beam propagation direction; (2 M −1) directional couplers; each coupler is formed by two waveguides, coming in and out of the coupler; a first output waveguide from each coupler forming an input waveguide for a subsequent optical coupler from (2 M −1) couplers; a final output waveguide from the last coupler forming a final output beam of the device; and wherein a portion of the final output beam is used in control means changing input phases in at least one input waveguide of each coupler to maximize the final output beam power, wherein the control means include a photodetector receiving the portion of the final output beam, producing an electrical signal being used to change the input phases in at least one input waveguide of each coupler, wherein the input phase is changed in a phase shifter connected to the same waveguide before coupling and wherein the electrical signal is used to change the coupling ratio of each coupler, wherein the coupling ratio change leads to maximization of the final output beam power receiving by the photodetector.