title: Near-infrared spectroscopy for monitoring water permeability of optical coatings on plastics.
abstract: Near-infrared spectroscopy has been applied to determine the water content of plastic lenses. An analytical method is presented for monitoring the water permeability of thin layers on plastic optics by utilizing the reversible moisture absorption of organic polymers. As an example, scratch-resistant and antireflective layers on poly[diethylenglycol-bis(allylcarbonate)] lenses are investigated. The measurements demonstrate the relatively high water barrier of coatings deposited by plasma-ion-assisted deposition compared with classical physical vapor deposition coatings and polysiloxane dip coatings.
authors.affiliation: Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Schillerstrasse 1, D-07745 Jena, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Schulz
authors.forename: N
authors.initials: N
authors.lastname: Kaiser