Variable flattened gaussian beam order selection by dynamic control of an intracavity diffractive mirror
In this paper we present the design of an optical resonator that produces as the stable transverse mode a flattened Gaussian laser beam by making use of an intra-cavity diffractive mirror. We consider the modal build-up in such a resonator and propose the required dynamic changes to an intra-cavity piezoelectric unimorph mirror for selecting the flattened Gaussian beam order of the stable mode. The feasibility of using a deformable diffractive mirror is demonstrated numerically. An optimization approach is employed to determine the optimal voltage distribution required to deform the mirror into a prescribed shape for the selection of the flattened Gaussian beam order. Good agreement between an ideal static diffractive mirror and the proposed adaptive mirror is achieved.