LASER Russian patent published in 1996 - IPC

FIELD: laser engineering. SUBSTANCE: laser has active medium 4, optical transmitting system, collimating system, spatial filter placed between them, and flat auxiliary mirrors forming multipass laser system. Optical transmitting system has transmitting mirror 2 in the form of telescopic lens with its partially reflecting concave side facing spatial filter 10, double-mirror lens placed between transmitting mirror 3 and filter 10 where mirror 9 in front of filter 10 is ring-shaped, and second mirror 3 is fixed on mirror 2, auxiliary concave mirror 1 on side of convex surface of transmitting mirror with hole whose diameter is greater than that of beam leaving the laser. Optical system focus on concave surface of mirror 2 and that of double-mirror lens are in hole of filter 10. Collimating system has convex mirror 13 and concave mirror 18; mirror 13 is placed between filter 10 and mirror 18 and has hole. Collimating system focus is in hole of filter 10. Focal lengths of transmitting and collimating systems coincide. Spatial filter has hole whose diameter is greater than of equal to diameter of central maximum of focal spot of collimating system annular beam. Hole is formed by edges of rotating disks whose surfaces on optical transmitting system side are toroidal. Flat auxiliary mirrors 11 and 12 are installed close to spatial filter for rotation; their center of revolution is displaced from optical axis of laser. Flat auxiliary mirrors form on one side of active medium trihedral angled reflectors, all remaining mirrors being located on other side of active medium. Optical transmitting system may have inclined flat transmitting mirrors and two trihedral angled reflectors placed on either side of transmitting mirror; revolving flat auxiliary mirror is located here close to spatial filter and perpendicular to optical axis. EFFECT: reduced beam divergence and sensitivity to maladjustment of wide-aperture lacers with low gain of active media. 12 cl, 10 dwg