Patent ID: 7626754

Claim:
A method for causing a light wave, having a complex amplitude and a wavefront, to propagate in a subset A of directions selected from a pre-defined set M of directions, while suppressing propagation of the light wave in a subset B of directions selected from the set M, wherein the method comprises the steps of: (a) providing an array of tunable phase delay elements disposed to interact with the light wave, for modifying the wavefront of the light wave in dependence upon control signals for controlling the array elements; (b) providing initial control signals for causing the light wave to propagate in the subset A of directions; (c) determining an initial complex amplitude of a fraction of the light wave propagating in the subset B of directions upon application of the initial control signals to the array elements; (d) determining perturbations to the initial control signals, for sending, in the subset B of directions, a wave having the modulus of the complex amplitude equal to the modulus of the initial complex amplitude, and the phase of the complex amplitude opposite to the phase of the initial complex amplitude; (e) applying the perturbations to the initial control signals, so as to produce adapted control signals; and (f) applying the adapted control signals to the array elements, so as to modify the wavefront of the light wave and facilitate propagation thereof in the subset A of directions while suppressing propagation thereof in the subset B of directions.