title: Making aspherical mirrors by thin-film deposition.
abstract: An aspherical mirror is made by a thin-film coating technique. A special mask is placed between the evaporation source and the substrate that is to be coated as an aspheric. The design principle of the mask is fully described. An ion-assisted deposition technique is used to relieve aluminum film stress and to increase surface reflectance. The final wave front is tested by conventional interferometric methods for aspherics. Less than one-fifth of a wave (632.8 nm) of spherical aberration is achieved without much trial and error.
authors.forename: C C
authors.initials: CC
authors.lastname: Lee
authors.forename: D S
authors.initials: DS
authors.lastname: Wan
authors.forename: C C
authors.initials: CC
authors.lastname: Jaing
authors.forename: C W
authors.initials: CW
authors.lastname: Chu