title: High-power fast-axial-flow CO2 laser with a variable-reflectivity output coupler.
abstract: We report what is to our knowledge the first cw, dc-excited, fast-axial-flow CO(2) laser using a variable-reflectivity output coupler. A super-Gaussian reflectivity profile of order 8 with 96% central reflectivity has been achieved by depositing a low-absorption coating onto a ZnSe substrate. The unstable resonator oscillated in the lowest-order mode to produce a diffraction-limited beam of 300 W of power and 0.35-mrad divergence angle (FWHM). The measured near field and far field are in good agreement with the mathematical model. The technique lends itself to extrapolation to the kilowatt level.
authors.affiliation: Euro Laser Technology, Westerring 19, B-9700 Oudenaarde, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Sona
authors.forename: P
authors.initials: P
authors.lastname: Muys
authors.forename: G
authors.initials: G
authors.lastname: Sherman
authors.forename: C
authors.initials: C
authors.lastname: Leys