Extraordinary transmission of organic photoluminescence through an otherwise opaque metal layer via surface plasmon cross coupling

We report extraordinary transmission of organic photoluminescence through an otherwise opaque, thin metal layer. We observe strong, angularly dependent photoluminescence from silver-coated films of ${\mathrm{Alq}}_3$ deposited on a corrugated substrate. Experimental and theoretical analysis indicates that light passes through the silver layer by cross coupling between surface plasmons on opposite sides of that layer. At narrow angles, the observed photoluminescence intensity is up to 10 times greater than that from a nonsilver-coated, uncorrugated organic film. This suggests an alternate device structure for efficient organic light emitting diodes.