  In this letter, we demonstrate for the first time that by combining the
effects of the Wood-Rayleigh Anomaly (WRA) and the Fabry-Perot (FP) resonance,
transmission efficiencies of $1$D metallo-dielectric gratings on substrates can
be significantly improved compared to when these two phenomena work separately.
Results of combining the WRA and the FP resonance can be utilized to eliminate
the necessity of using the index matching technique and the core-shell
structure for enhancing the performance of extraordinary optical transmission
devices. Further, the outcomes of combining the WRA and the FP resonance can
elucidate some of the unexplained results in the literature.
