Coupling of laser arrays with intracavity elements in the far-field

A relatively simple technique for coupling lasers in an array is presented. It is based on the insertion of an intracavity optical element in the far-field plane of a degenerate cavity laser that is used to form an array of lasers. We show that it is possible to control the selection of the lasers to couple regardless of the array geometry. An intracavity spherical lens in the far-field plane is numerically and experimentally investigated and the results compared with those from the more complicated Talbot diffraction for coupling lasers. With an intracavity cylindrical lens in a two dimensional square array geometry, it is possible to obtain controlled one-dimensional coupling, and with an intracavity binary phase element it is possible to obtain versatile couplings.