Yu Haiwu, Bourdet Gilbert
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.
Appl Opt. 2005 Nov 20;44(33):7161-9. doi: 10.1364/ao.44.007161.
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.
利用准三能级激光离子理论，我们得出了Yb:YAG增益介质的最佳厚度。对于二极管泵浦Lucia激光器（超短超强激光及其应用）的振荡器和放大器参数，其将输出100 J、10 Hz、10 ns的脉冲序列，最佳厚度分别为1.4和1.6 mm，浓度为10 at.%。模拟表明，如此薄的介质弯曲程度很大，但可以通过替换复合增益介质来消除。未掺杂YAG的最佳厚度与Yb:YAG的最佳厚度相关，并且还取决于冷却条件。结果表明，对于小口径振荡器，在几种掺杂浓度下我们都可以获得最小弯曲和光学畸变。然而，对于大口径放大器，较高的掺杂（约20 at.%）更为可取。所报道的结果将有助于高平均功率薄片Yb:YAG激光器增益介质的设计。
