\begin{table}%t1
\caption{\label{table:1}Doppler factors for evaluation of the stimulated emission rates.}
%\centering
\par
\begin{tabular}{c c c c}  
\hline\hline
Normalized stimulated & \multicolumn{3}{c}{Doppler factors $\mathcal{D}$ for 
evaluating}  \\
emission rate & $n_+$ & $n_0$ & $n_-$\\
\hline \noalign{\smallskip}
$R_+$ &  1  & \large $\frac{\omega_{\rm R}+g\Omega/2}{\omega_{\rm R}}$ &
              \large $\frac{\omega_{\rm R}+g\Omega/2}{\omega_{\rm R}-g\Omega/2}$ \\[-2mm]
 %     &     &      &     \\
$R_0$ & \large $\frac{\omega_{\rm R}+g\Omega/2}{\omega_{\rm R}}$ & 1 & 
        \large $\frac{\omega_{\rm R}}{\omega_{\rm R}-g\Omega/2}$                 \\[-2mm]
 %     &     &      &     \\
$R_-$ & \large $\frac{\omega_{\rm R}-g\Omega/2}{\omega_{\rm R}+g\Omega/2}$ &
        \large $\frac{\omega_{\rm R}-g\Omega/2}{\omega_{\rm R}}$           &  1   \\
\hline
\end{tabular}
\end{table}