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\begin{document}

\begin{center}
{\bf \Large Redes de difracci\'on}
\end{center}

Campo de interferencia producido por $N$ rendijas de ancho $a$ y
espaciamento $b$:
\begin{equation}
I = I_{\circ} \left[ \frac{\sin(\frac{\pi}{\lambda} a
\sin(\theta))}{\frac{\pi}{\lambda}a\sin(\theta)}  \frac{
\sin(\frac{\pi}{\lambda} N b
\sin(\theta))}{\sin(\frac{\pi}{\lambda}b\sin(\theta))} \right]^{2}
\end{equation}

Ejemplos para $\lambda=5000$\AA, $a=1$mm, $b=5$mm:

\vspace{0.5cm}
\[{\bf N=2} \]
\begin{center}
\resizebox{\textwidth}{!}{\rotatebox{-90}{\epsfig{file=interf_2.ps}}} 
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\resizebox{\textwidth}{!}{\rotatebox{-90}{\epsfig{file=interf_2_im.ps}}} 
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\newpage

\[{\bf N=3 }\]
\begin{center}
\resizebox{\textwidth}{!}{\rotatebox{-90}{\epsfig{file=interf_3.ps}}} 
\end{center}

\vspace{0.5cm}
\[{\bf N=100} \]
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\resizebox{\textwidth}{!}{\rotatebox{-90}{\epsfig{file=interf_100.ps}}} 
\end{center}

\end{document}