In this paper we present the analytical and numerical analyses of two new resonator systems for generating flat-top-like beams. Both approaches lead to closed form expressions for the required cavity optics, but differ substantially in the design technique, with the first based on reverse propagation of a flattened Gaussian beam,
and the second a metamorphosis of a Gaussian field into a flat-top beam. We show that both have good
convergence properties, and result in the desired stable mode.