Main properties and potential practical applications of M-mode lasers

The results are given of experimental and theoretical investigations of the properties of multipass-mode (M-mode) lasers. Methods of improving the characteristics of these lasers, including low-divergence and single-frequency lasing, are considered. The following applications of M-mode lasing are discussed: energy extraction from a medium in the shape of a ring, active formation of images, and interferometry of wide-aperture objects.