title: Local determination of thin liquid film profiles using colour interferometry.
abstract: We explore theoretically the interference of white light between two interfaces as a function of the optical conditions, using separately: a) idealised conditions where the light is composed of three discrete wavelengths; b) a more typically experimentally realisable case where light comprises a sum of three Gaussian wavelength distributions; and c) unfiltered white light from a broadband source comprising a broad distribution of wavelengths. It is demonstrated that the latter case is not only optically simple to arrange, but also provides unambiguous absolute separation information over the range 0-1μm --a useful range in studies of cell adhesion, thin liquid films and lubrication-- when coupled to detection using a typical colour camera. The utility of this technique is verified experimentally by exploring the air film between a cylinder and surface, as well as arbitrary liquid films beneath air bubbles that are interacting with solid surfaces.
authors.affiliation: School of Chemistry, Monash University, 3800, Clayton, Australia.
authors.forename: Calum S
authors.initials: CS
authors.lastname: Butler
authors.affiliation: School of Chemistry, Monash University, 3800, Clayton, Australia.
authors.forename: Zoe L E
authors.initials: ZL
authors.lastname: Seeger
authors.affiliation: School of Chemistry, Monash University, 3800, Clayton, Australia.
authors.forename: Toby D M
authors.initials: TD
authors.lastname: Bell
authors.affiliation: School of Physics, Monash University, 3800, Clayton, Australia.
authors.forename: Alexis I
authors.initials: AI
authors.lastname: Bishop
authors.affiliation: School of Chemistry, Monash University, 3800, Clayton, Australia. rico.tabor@monash.edu.
authors.forename: Rico F
authors.initials: RF
authors.lastname: Tabor
mesh_terms: D000388:Air; D003116:Color; D007368:Interferometry; D008027:Light; D016011:Normal Distribution; D055620:Optical Phenomena
keywords: Topical Issue: Wetting and Drying: Physics and Pattern Formation