title: Ellipsometry with randomly varying polarization states.
abstract: We show that, under the right conditions, one can make highly accurate polarization-based measurements without knowing the absolute polarization state of the probing light field. It is shown that light, passed through a randomly varying birefringent material has a well-defined orbit on the Poincar sphere, which we term a generalized polarization state, that is preserved. Changes to the generalized polarization state can then be used in place of the absolute polarization states that make up the generalized state, to measure the change in polarization due to a sample under investigation. We illustrate the usefulness of this analysis approach by demonstrating fiber-based ellipsometry, where the polarization state of the probe light is unknown, and, yet, the ellipsometric angles of the investigated sample (Ψ and Δ) are obtained with an accuracy comparable to that of conventional ellipsometry instruments by measuring changes to the generalized polarization state.
authors.affiliation: FOM-Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Lee
authors.forename: Juequan
authors.initials: J
authors.lastname: Chen
authors.forename: Eric
authors.initials: E
authors.lastname: Louis
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: van der Slot
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Boller
authors.forename: Fred
authors.initials: F
authors.lastname: Bijkerk
mesh_terms: D001718:Birefringence; D002244:Carbon; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D054020:Lasers, Gas; D008027:Light; D008962:Models, Theoretical; D009356:Neon; D055100:Optical Fibers; D015203:Reproducibility of Results
chemical_list: D009356:Neon; D002244:Carbon