title: Ultra-wide-range measurements of thin-film filter optical density over the visible and near-infrared spectrum.
abstract: We present the improved structure and operating principle of a spectrophotometric mean that allows us for the recording of the transmittance of a thin-film filter over an ultra-wide range of optical densities (from 0 to 11) between 400 and 1000 nm. The operation of this apparatus is based on the combined use of a high power supercontinuum laser source, a tunable volume hologram filter, a standard monochromator and a scientific grade CCD camera. The experimentally recorded noise floor is in good accordance with the optical density values given by the theoretical approach. A demonstration of the sensitivity gain provided by this new set-up with respect to standard spectrophotometric means is performed via the characterization of various types of filters (band-pass, long-pass, short-pass, and notch).
authors.forename: Michel
authors.initials: M
authors.lastname: Lequime
authors.forename: Simona
authors.initials: S
authors.lastname: Liukaityte
authors.forename: Myriam
authors.initials: M
authors.lastname: Zerrad
authors.forename: Claude
authors.initials: C
authors.lastname: Amra