title: Optical coatings with variable reflectance for laser mirrors.
abstract: Design procedures and fabrication techniques of variable reflectance dielectric mirrors for laser output couplers are proposed. The design criteria, based on the use of only one shaped layer in a multilayer structure, yield any peak value and shape of the reflectance profile. The deposition technique of the variable thickness layer consists of a sputtering process with a suitable mask interposed between the target and substrate. Results of a simple model that correlates the mirror parameters to mask diameter and position are presented. A few devices for a Nd:YAG laser have been proposed, characterized, and successfully tested in a laser resonator.
authors.forename: G
authors.initials: G
authors.lastname: Emiliani
authors.forename: A
authors.initials: A
authors.lastname: Piegari
authors.forename: S
authors.initials: S
authors.lastname: De Silvestri
authors.forename: P
authors.initials: P
authors.lastname: Laporta
authors.forename: V
authors.initials: V
authors.lastname: Magni