\begin{table}%T2
\caption{Fabry-Perot interferometer characteristics.}
\label{tab:fp.characteristics}
%\centering
\small
\begin{tabular}{ll}
\hline\hline\noalign{\smallskip}
Manufacturer                                 &IC Optical Systems               \\
Type                                         &ET50 FS                          \\
Clear aperture (mm)                          &50                               \\
Plate spacing (mm)                           &2.300 (FPI \#1), 0.637 (FPI \#2)  \\ %$\pm 1 {\mu}$m\\
Wedge angle                                  &20$^{\prime}$                    \\
Coating                                      &Multilayer broadband             \\
Dispersion (\AA/step)                     & 4.80  (FPI \#1), 4.59 (FPI \#2) \\
Wavelength range (\AA)                       & 5800~--~8600                      \\
Nominal reflectance (@ 6328~\AA)             & 0.942                            \\
Nominal absorption coefficient               &$\le$0.002                      \\
Estimated cavity errors \\
 (@ 6328~\AA)           &$\lambda$/150 (after coating)    \\
\noalign{\smallskip}\hline
\end{tabular}
\end{table}