Some progress on optimal $ 2 $-D $ (n\times m,3,2,1) $-optical orthogonal codes

In this paper, we are concerned about bounds and constructions of optimal \begin{document}$ 2 $\end{document} -D \begin{document}$ (n\times m,3,2,1) $\end{document} -optical orthogonal codes. The exact number of codewords of an optimal \begin{document}$ 2 $\end{document} -D \begin{document}$ (n\times m,3,2,1) $\end{document} -optical orthogonal code is determined for \begin{document}$ n = 2 $\end{document} , \begin{document}$ m\equiv 1 \pmod{2} $\end{document} , and \begin{document}$ n\equiv 1 \pmod{2} $\end{document} , \begin{document}$ m\equiv 1,3,5 \pmod{12} $\end{document} , and \begin{document}$ n\equiv 4 \pmod{6} $\end{document} , \begin{document}$ m\equiv 8 \pmod{16} $\end{document} .