title: Measurement of film thickness up to several hundreds of nanometers using optical waveguide lightmode spectroscopy.
abstract: Up to now, most studies based on optical waveguide lightmode spectroscopy (OWLS) were dedicated to thin adlayers, assumed to be isotropic and homogeneous, for which data analysis was based on an approximation of the mode equations valid when the thickness is small with respect to the wavelength of the laser light. The aim of the present paper is to extend the use of OWLS to thicker deposited layers (up to approximately 400 nm). Both the simplified and extended models are compared in terms of optical parameters, i.e. the refractive index nA, the thickness dA, and the optical mass QA, for experimental data obtained with polyelectrolyte multilayer films. The deviation of these parameters can be quite large when derived using the simplified model instead of the extended model. This observation evidences that OWLS is well suited for the study of "thick" films if the appropriate model is applied to the data analysis.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, Unité 595, Faculté de Chirurgie Dentaire, Université Louis Pasteur, 11 rue Humann, 67085 Strasbourg Cedex, France. catherine.picart@medecine.u-strasbg.fr
authors.forename: Catherine
authors.initials: C
authors.lastname: Picart
authors.forename: Csilla
authors.initials: C
authors.lastname: Gergely
authors.forename: Youri
authors.initials: Y
authors.lastname: Arntz
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Voegel
authors.forename: Pierre
authors.initials: P
authors.lastname: Schaaf
authors.forename: Frédéric J G
authors.initials: FJ
authors.lastname: Cuisinier
authors.forename: Bernard
authors.initials: B
authors.lastname: Senger
mesh_terms: D000465:Algorithms; D020099:Coated Materials, Biocompatible / Q000032:analysis* / Q000737:chemistry*; D008567:Membranes, Artificial; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000032:analysis / Q000737:chemistry; D012031:Refractometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D020099:Coated Materials, Biocompatible; D008567:Membranes, Artificial; D011108:Polymers