%%
%%  Ein Beispiel der DANTE-Edition
%%
%%
%%  Copyright (C) 2010 Herbert Voss
%%
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%%
%%  See http://www.latex-project.org/lppl.txt for details.
%%
%%
%% ====
% Show page(s) 1
%%
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{190.324pt}
\setlength\parindent{0pt}
\StartShownPreambleCommands
\usepackage{pst-optic}
\StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-8,-2)(8,5.75)
 \pnode(-8,1.5){A}\pnode(8,1.5){B}
 \uput[45](A){A}\uput[135](B){B}
 \pnode(0,0){START}
 \psframe[fillcolor=lightgray,fillstyle=solid,linecolor=blue](-8,-1.5)(B)
 \psset{linecolor=red,arrowsize=3pt,arrows=->}
 \multido{\n=20+5}{29}{%
   \refractionRay(START)(1;\n)(A)(B){1.5}{1}{END}
   \arrowLine(START)(END){2}\arrowLine(END)(END'){1}
   \psOutLine[length=3](END)(END'){Q}\arrowLine(END')(Q){3} }
\end{pspicture}
\end{document}