Procedure to characterize microroughness of optical thin films: application to ion-beam-sputtered vacuum-ultraviolet coatings

• DOI: 10.1364/ao.40.002190
• Publication Date: 2007-08-16T16:48:39Z
• Authors: Josep Ferré-Borrull; Angela Duparré; Etienne Quesnel
• Keywords: Optical coating; Vacuum ultraviolet; Extreme ultraviolet

A method for characterizing the microroughness of samples in optical coating technology is developed. Measurements over different spatial-frequency ranges are composed into a single power spectral density (PSD) covering large bandwidth. This followed by extraction characteristic parameters through fitting PSD to suitable combination theoretical models. The allows us combine measurements performed with techniques, and procedure can be adapted any behavior combined PSD. has been applied set ion-beam-sputtered fluoride vacuum-UV coatings increasing number alternative low- high-index layers. Conclusions about roughness development microstructural growth drawn.