title: Absorption of low-loss optical materials measured at 1064 nm by a position-modulated collinear photothermal detection technique.
abstract: A collinear photothermal detection bench is described that makes use of a position-modulated heating source instead of the classic power-modulated source. This new modulation scheme increases by almost a factor 2 the sensitivity of a standard mirage bench. This bench is then used to measure the absorption coefficient of OH-free synthetic fused silica at 1064 nm in the parts per 10(6) range, which, combined with spectrophotometric measurements, confirms that the dominant absorption source is the OH content.
authors.affiliation: Ecole Supérieure de Physique et Chimie Industrielles de la Ville de Paris, Laboratoire d'Optique Physique, Centre National de la Recherche Scientifique, Unité Propre de Recherche 5, 10 rue Vauquelin, 75005 Paris, France. loriette@optique.espci.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: Loriette
authors.forename: Claude
authors.initials: C
authors.lastname: Boccara