ELECTROOPTIC REFLECTION WITH SURFACE-PLASMONS

Electrooptic reflection with surface plasmons is studied both experime ntally and theoretically. An attenuated total reflection (ATR) geometr y is used in which a quartz electrooptic crystal onto which a thin Ag film has been evaporated is contacted to the hypotenuse face of a high -index prism. Modulation in the ATR of an He-Ne beam near the angle fo r surface plasmon excitation is observed when a low-frequency electric field is applied to the quartz crystal. Experiments have been done wi th both single and multiple boundary surface waves. The angular spectr a show phase reversal structure due to the interference of the modulat ed reflected wave with the ATR wave. The modulated reflectance is calc ulated directly from a well-known solution to the boundary value probl em in nonlinear optics. Good quantitative agreement with the observati ons is obtained.