Design of dammann-gratings for array generation

Abstract

Specially designed binary phase gratings (“Dammann-gratings”) split an incoming wave into a regular array of similar waves of equal intensity. The difficulties in the design procedure by nonlinear optimization increase with the size of the required array that is with the number of diffraction orders. All possible Dammann-gratings (with phase values of 0 and π) with up to 21 equal diffraction orders in one dimension have been designed. They are compared in terms of light efficiency, feature sizes and sensitivity to errors. A catalogue of the best designs is given.