Optical phased array

This paper presents the case of an optical phased array in analogy with its counterpart in the microwave frequency region. It consists of a planar aperture array formed by the discrete illuminated core ends of a number of monomode optical fibres placed adjacent to each other in several rows. The essence of its operation lies in the production of phase shift on the application of a de electric field by using the slight non-linear property of the fibre material. Generation of multiple beams due to the large size of fibre diameter in comparison to wavelength is avoided by producing an appropriately demagnified real image of the terminal end plane of the bunch of fibres. The real image plane now acts as the array of radiators and phase scanning is obtained by producing required phase shift in each fibre.