Compact and simple configurations for converting laser beam distributions

In this paper, we present a relatively simple and practical approach for efficiently conversing of a single high-order mode intensity distribution to a nearly Gaussian distribution. It is based on dividing the high-order mode distribution into equal parts that are then combined together coherently. Experimentally we implement this approach with single interferometric elements, whose surfaces are specially coated. With single interferometric element, the interferometric stability is significantly improved and the complexity of alignment is reduced.