UNSTABLE MULTIREENTRANT LASER RESONATOR Russian patent published in 1995 - IPC

FIELD: laser equipment. SUBSTANCE: unstable multireentrant laser resonator includes two terminating concave mirrors and even number of intermediate mirrors. Mirrors with radio of curvature of long-focused terminating mirror installed confocally to each other and two terminating mirrors are used as intermediate mirrors. In this case decrease of energy concentration on intermediate mirrors is achieved thanks to confocal mounting of all mirrors, diminished sensitivity to misalignments is obtained thanks to reduced effective length of resonator which leads to increase of Fresnel number and consequently to increase of energy efficiency. EFFECT: increased energy efficiency. 2 dwg