Исходники иллюстрации

\documentclass[tikz]{standalone}\input{pre.tex}\begin{document}\begin{tikzpicture}
    % \xdef\darkness{0}
    % \xdef\op{0.1}

    % \xdef\SIZE{10}

    % \draw[step=1.0,blue,thick,opacity=\op] (0,0) grid (\SIZE,\SIZE);
    % \draw[step=0.5,blue,very thin,opacity=\op] (0,0) grid (\SIZE,\SIZE);

    % \foreach \i in {0,1,...,\SIZE} {
 %      \draw[opacity=\op] (0,\i) node [left] {\i};
 %      \draw[opacity=\op] (\i,0) node [below] {\i};
 %    }

\begin{scope}[xshift=-3cm]
    \draw [thick] (0,0) node [left] {$E_1$} -- ++(2,0);
    \draw [thick] (0,2.5) node [left] {$E_2$} -- ++(2,0);
    \draw[fill=black] (1,2.5) circle (5pt);
\end{scope}

\begin{scope}[xshift=0cm]
    \draw [thick] (0,0) node [left] {$E_1$} -- ++(2,0);
    \draw [thick] (0,2.5) node [left] {$E_2$} -- ++(2,0);
    \draw[thick,->] (1,2.5) -- (1,5pt);
    \draw[dashed, fill=white] (1,2.5) circle (5pt);

    \draw[fill=black] (1,0) circle (5pt);
    \draw [decorate, magenta, decoration={snake}, ->] (1,1.25) --
    node [below,sloped]{$h\nu$} ++(1,0); 
\end{scope}

\begin{scope}[xshift=3cm]
    \draw [thick] (0,0) node [left] {$E_1$} -- ++(2,0);
    \draw [thick] (0,2.5) node [left] {$E_2$} -- ++(2,0);
    % \draw[thick,->] (1,2.5) -- (1,5pt);
    % \draw[dashed, fill=white] (1,2.5) circle (5pt);

    \draw[fill=black] (1,0) circle (5pt);
    \draw [decorate, magenta, decoration={snake}, ->] (1,1.25) --
    node [below,sloped]{$h\nu$} ++(1,0); 
\end{scope}

    \node [align=center] () at (-3+1,-1) {Возбужденное \\ состояние атома};
    \node [align=center] () at (3+1,-1) {Основное \\ состояние атома};

    \node [align=center] () at (-3+1,2.5+1) {До эмиссии};
    \node [align=center] () at (0+1,2.5+1) {Эмиссия};
    \node [align=center] () at (3+1,2.5+1) {После эмиссии};



\end{tikzpicture}\end{document}