title: Nonlinear absorption in single LaF(3) and MgF(2) layers at 193 nm measured by surface sensitive laser induced deflection technique.
abstract: We report nonlinear absorption data of LaF(3) and MgF(2) single layers at 193 nm. A highly surface sensitive measurement strategy of the laser induced deflection technique is introduced and applied to measure the absorption of highly transparent thin films independently of the substrate absorption. Linear absorptions k=(alphaxlambda)/4pi of 2x10(-4) and 8.5x10(-4) (LaF(3)) and 1.8x10(-4) and 6.9x10(-4) (MgF(2)) are found. Measured two photon absorption (TPA) coefficients are beta=1x10(-4) cm/W (LaF(3)), 1.8x10(-5), and 5.8x10(-5) cm/W (MgF(2)). The TPA coefficients are several orders of magnitude higher than typical values for fluoride single crystals, which is likely to result from sequential two step absorption processes.
authors.affiliation: Institute of Photonic Technology, Albert-Einstein-Strasse 9, 07745 Jena, Germany. christian.muehlig@ipht-jena.de
authors.forename: Christian
authors.initials: C
authors.lastname: Mühlig
authors.forename: Simon
authors.initials: S
authors.lastname: Bublitz
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kufert