We　study　the　dynamics　of　a　system　composed　of　two　coupled　cavities,　each　interacting　with　a　single　Rydberg　atom.　The　interplay　between　Rydberg-Rydberg　interaction　and　photon　hopping　enables　the　transition　of　the　atoms　from　the　collective　ground　state　to　the　double　Rydberg　excitation　state　by　individually　interacting　with　the　optical　normal　modes　and　suppressing　the　upconversion　process　between　them.　The　atomic　transition　is　accompanied　by　the　two-photon　absorption　and　emission　of　the　normal　modes.　Since　the　energy　level　structure　of　the　atom-cavity　system　is　photon　number　dependent　there　is　only　a　pair　of　states　being　in　the　two-photon　resonance.　Therefore,　the　system　can　act　as　a　quantum　nonlinear　absorption　filter　through　the　nonclassical　quantum　process,　converting　coherent　light　field　into　a　nonclassical　state.　Meanwhile,　the　vacuum　field　in　the　cavity　inspires　the　Rydberg　atoms　to　simultaneously　emit　two　photons　into　the　normal　mode,　resulting　in　obvious　emission　enhancement　of　the　mode.　©　2013　American　Physical　Society.