Output properties of diode-pumped passively Q-switched 1.06 μm Nd:GdVO4 laser using a [100]-cut Cr4+:YAG crystal

A passively Q-switched 1.06 μm Nd:GdVO4 laser with a [100]-cut Cr4+:YAG saturable absorber was demonstrated. The output characteristics were investigated when the anisotropic transmission of Cr4+:YAG crystal and the incident pump power level were considered. The experimental results showed that it was feasible to generate laser with narrower pulse width (τp), higher pulse energy and peak power when the polarization direction of laser was parallel to the [001], [010], [\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$00\overline{1}$\end{document}], and [\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$0\overline{1}0$\end{document}] orientations of the Cr4+:YAG crystal. The different changes of τp as a function of incident pump power was observed due to the anisotropy of transmission of Cr4+:YAG and the different gain levels (pump power levels). If the Cr4+:YAG was fully bleached as a result of high cavity gain or due to the laser polarization direction was parallel to the [001], [010], [\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$00\overline{1}$\end{document}], and [\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$0\overline{1}0$\end{document}] orientations, τp was constant, otherwise τp decreased when the gain increased.