A.M.Zabelin.

Device for laser treating includes power gas laser, system of beam transmitting and focusing, and adjusted telescope. With the purpose of aberrations and dimensions decrease, by constancy of high power and efficiency, the adjusted telescope is made from cylindrical mirrors and laser has an output beam, drawn in direction of telescope compression. As the resonator of laser, producing a beam with elliptic section, the unstable, stable and stable-unstable resonator can be used, which caustic fills almost all gap of excitation cabinet. For quality increase of output beam it is offered to realize a beam spatial filtration in plane of compression, erecting in a focal plane of telescope the slit filter. Thus, as contrasted to spherical telescope, the smaller intensity of beam in focus of telescope is reached and the breakdown on edge of diaphragm is prevented.