title: Model for the calculation of radiation trapping and description of the pinhole method.
abstract: Radiation trapping is a well-known process that results in the lengthening of observed fluorescence lifetimes in laser materials with significant overlap in their emission and absorption spectra. The pinhole method is a measurement technique that allows the intrinsic fluorescence lifetime of an excited state to be determined in a nondestructive manner. A theoretical description of this method is proposed. A model is developed that identifies the lifetime extrapolated to a zero radius pinhole as the intrinsic fluorescence lifetime. The application of this method to bulk materials and thin discs is discussed.
authors.affiliation: Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany. HKuehn@physnet.uni-hamburg.de
authors.forename: Henning
authors.initials: H
authors.lastname: Kühn
authors.forename: Susanne T
authors.initials: ST
authors.lastname: Fredrich-Thornton
authors.forename: Christian
authors.initials: C
authors.lastname: Kränkel
authors.forename: Rigo
authors.initials: R
authors.lastname: Peters
authors.forename: Klaus
authors.initials: K
authors.lastname: Petermann