Patent ID: 7813405

Claim:
A method for minimizing odd order aberration in an unstable laser disk resonator of the type having an optical cavity with an optical axis, Primary and Secondary end mirrors disposed at opposite ends of the optical axis, and one or more 1:1 laser disk imaging systems disposed in cascade between the Primary and Secondary end mirrors, from a first imaging system disposed adjacent to and in direct optical communication with the Secondary mirror and a last imaging system disposed adjacent to and in direct optical communication with the Primary end mirror, the imaging systems in combination with the end mirrors providing a negative branch imaging resonator (NBIR), each imaging system including a laser disk and a reflecting mirror, each having a concave spherical mirror surface, and together disposed in a confocal, mutually oblique relationship that extends as a W configuration array to provide full self imaging of each 1:1 imaging system output signal onto an adjoining imaging system, the method comprising: inserting a first single coupling mirror between the Secondary end mirror and the laser disk of the first imaging system, and inserting a second single coupling mirror between the Primary end mirror and the reflecting mirror of the last imaging system at a position in order to maintain NBIR performance characteristics of the unstable laser disk resonator, thereby providing indirect optical communication between the end mirrors and the 1:1 imaging systems, thereby eliminating direct optical communication between the 1:1 imaging systems and the Secondary and Primary end mirrors.