Formation of the radial distribution of intensity in a laser beam by "soft" apertures

The results are given of theoretical and experimental investigations of "soft" apertures whose action is based on the dependence of the transmission of light by a three-layer medium on the thickness of the layer separating the surfaces on which light is incident at an angle exceeding the angle of total internal reflection. It is shown that such apertures can be used to form a beam with a specified radial intensity profile from beams with Gaussian and uniform profiles. The high optical strength of such apertures and the possibility of formation of a radial profile with a high spatial fill factor without formation of diffraction rings makes them suitable for use in high-power laser systems.