Whispering gallery mode propagation in photonic crystals in front of subwavelength slit arrays

► We show that whispering gallery mode excitation in a molecular photonic crystal couples and dominates the transmission of subwavelength slit arrays.We show selection of the transport and confinement of energy characteristics. ► We study grating beaming by introducing periodic corrugation in the slit slab. ► We show how the photonic crystal enhances transmission through the slits.