\begin{table}%T1
  \caption{Design of the two binary checkerboard mask.}\label{table01}
  \small
  %\centerline
 {
    \begin{tabular}{lcc}
\hline
\hline
                         & Mask~1 & Mask~2\\
\hline
      Type               & Symmetric   &  Symmetric \\
      Central obstruction   & 30\%       &  No obstruction \\
      IWA$^{*}$($\lambda/D$)      & 7          &  3   \\
      OWA$^{*}$($\lambda/D$)      & 16         &  30 \\
      Contrast              & 10$^{-7}$     &  10$^{-7}$ \\
      Throughput$^{**}$(\%)           &  16          &  24      \\
\hline
    \end{tabular}
 }\smallskip
     \small{
      $^*$ In the experiment the wavelength was $\lambda$ = 632.8~nm, 
          and
          the diameter of the entrance pupil was $D$~=~2~mm
        (the binary mask is inscribed to this pupil).
     $^{**}$ Ratio of the transmissive area of the mask to the whole area
       for an assumed entrance pupil diameter of 2~mm.
       }
\end{table}