title: Thickness optimization of the composite gain medium for the oscillator and amplifier of the lucia laser.
abstract: Using a theory of quasi-three-level laser ions, we obtained the optimum thickness of the gain medium of Yb:YAG. For the parameters of the oscillator and the amplifier of the diode-pumped Lucia laser (Lasers Ultra-Courts et Intense et Applications), which will deliver a 100 J, 10 Hz, 10 ns pulse train the optimum thicknesses are, respectively, 1.4 and 1.6 mm, with a concentration of 10 at. %. Simulations indicate that the bending of such a thin medium is great but can be eliminated by substitution of a composite gain medium. The optimum thickness of undoped YAG is related to that of Yb:YAG and is also dependent on cooling conditions. Results show that, for a small-aperture oscillator, we can obtain both minimum bending and optical distortion at several doping concentrations. However, greater doping (approximately 20 at. %) is preferred for a large-aperture amplifier. The results reported will be helpful for the design of gain media for high-average-power thin disk Yb:YAG lasers.
authors.affiliation: Laboratoire pour l'Utilisation des Lasers Intense, Unité Mixte de Recherche 7605, Ecole Polytechnique, Centre National de la Recherche Scientifique, Commisariat a l'Energie Atomique and Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex, France.
authors.forename: Haiwu
authors.initials: H
authors.lastname: Yu
authors.forename: Gilbert
authors.initials: G
authors.lastname: Bourdet