title: Application of the concept of effective refractive index to the measurement of thickness distributions of dielectric films.
abstract: In the method to be described, the dielectric film is deposited between two silver films so that the threelayer system constitutes a Fabry-Perot interference filter. It is shown how measurements of the variation of the wavelength of peak transmittance over the surface of the filter can be combined with a measurement of the effective refractive index to obtain precise values of the distribution of relative geometrical thickness of the dielectric spacing layer.
authors.affiliation: Royal College of Advanced Technology,Salford 5, England.
authors.forename: D
authors.initials: D
authors.lastname: Keay
authors.forename: P H
authors.initials: PH
authors.lastname: Lissberger