Formation of non-Gaussian light beams with the aid of a spatially inhomogeneous amplitude filter

A description is given of a nonabsorbing spatially inhomogeneous amplitude filter designed for the transformation of laser beam profiles without introducing small-scale irregularities of the beam amplitude and phase. Experiments carried out using an He–Ne laser showed that it was possible to form beams with a flat top carrying 33% of the power of the original Gaussian beam. A filter of this kind could also be used to produce other beam profiles, for example, one with a dip on the axis.