Theoretical Study of the Nonlinear Response Function in Metal Optics

As we know the light interacting with metal surface or interfaces can excite longitudinal plasma waves inside the metal. This phenomenal becomes more important at frequencies of the order of metal plasma frequencies (??=10ev). This is the region in which the advent of synchrotron radiation has opened up a rapidly growing find of optical experiments. One can demonstrate that reflection from and transmission through metal layers, electro reflection and ellipsometry from metal surfaces, the surface Plasmon and Eigen modes in this layer and spheres and also the field wear the surface as encountered by the photoemission. These things cannot be under stood been qualitatively without taking plasma waves into account.