title: Large effective fresnel number confocal unstable resonators: an experimental study.
abstract: An experimental study was performed on the beam quality of large equivalent Fresnel number positive confocal unstable square resonators in a CO(2) electron-beam ionized laser. Near diffraction limited output was observed for a range of geometric output coupling from 34% to 85%, with a sensitivity to the particular value of equivalent Fresnel number being found only for the lowest output coupling.
authors.forename: H
authors.initials: H
authors.lastname: Granek
authors.forename: A J
authors.initials: AJ
authors.lastname: Morency