Optical response of nanostructured surfaces: experimental investigation of the composite diffracted evanescent wave model

The past decade has seen a rapidly developing interest in the response of subwavelength-structured surfaces to optical excitation. Many studies have interpreted the optical coupling to the surface in terms of surface plasmon polaritons, but recently another approach involving diffraction of surface evanescent waves, the Composite Diffractive Evanescent Wave (CDEW) model has been proposed. We present here a series of measurements on very simple one-dimensional (1-D) subwavelength structures with the aim of testing key properties of the surface waves predicted by the CDEW model.