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);
%   \draw [decorate, magenta, decoration={snake}, ->] (0,1.25) --
%     node [below,sloped, align=center, scale=0.6, yshift=-4pt]{фотон\\ спонтанного\\ излучения} ++(1,0);     
% \end{scope}

\begin{scope}[xshift=0cm]
    \draw [thick] (0,0) node [left] {$E_1$} -- ++(3,0);
    \draw [thick] (0,2.5) node [left] {$E_2$} -- ++(3,0);
    \foreach \i in {0.5,1,...,2.5} {
        \draw[fill=black] (\i,0) circle (5pt);
    }    
    \foreach \i in {0.5,1,...,2.5} {
        \draw[dashed, fill=white] (\i,2.5) circle (5pt);
    }        
    \draw[fill=black] (0.5,2.5) circle (5pt);
    \draw[fill=black] (1,2.5) circle (5pt);
\end{scope}

\begin{scope}[xshift=6cm]
    \draw [thick] (0,0) node [left] {$E_1$} -- ++(3,0);
    \draw [thick] (0,2.5) node [left] {$E_2$} -- ++(3,0);
    \foreach \i in {0.5,1,...,2.5} {
        \draw[fill=black] (\i,2.5) circle (5pt);
    }    
    \foreach \i in {0.5,1,...,2.5} {
        \draw[dashed, fill=white] (\i,0) circle (5pt);
    }        
    \draw[fill=black] (0.5,0) circle (5pt);
    \draw[fill=black] (1,0) circle (5pt);
\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}, ->] (1,1.5) --
%     node [above,sloped]{} ++(1,0); 

%   \draw [decorate, magenta, decoration={snake}, ->] (1,1) --
%     node [below,sloped]{} ++(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}