title: Photopolarimeter based on two gratings recorded in thin organic films.
abstract: A photopolarimeter based on two different kinds of diffraction gratings (a two-grating photopolarimeter) has been developed for real-time measurements of the four elements of the Stokes vector. The main elements of the device are a pure polarization grating and an ordinary transmission grating, both recorded by means of holographic techniques in thin films of organic materials. The first one consists of a diffraction grating recorded by two interfering opposite circularly polarized beams in a Langmuir-Blodgett film of an azo-compound material. The second component is a grating recorded by two interfering parallel circularly polarized beams in a thin film of a photosensitive polymer. Both gratings offer long time stability and good diffraction efficiency. Four photodiodes collect the first-order diffracted beams from these gratings, the output signals of which are read through an analog-to-digital converter by a PC. The optical alignment of the device is easy and the calibration is realized in a one-step procedure.
authors.affiliation: Dipartimento di Fisica and Excellence Centre, CEMIF.CAL, Università della Calabria, Rende, Italy.
authors.forename: Clementina
authors.initials: C
authors.lastname: Provenzano
authors.forename: Gabriella
authors.initials: G
authors.lastname: Cipparrone
authors.forename: Alfredo
authors.initials: A
authors.lastname: Mazzulla