We observed enhanced reflected second-harmonic generation (SHG) that was due to coupled surface-plasmon modes in thin silver films separated with a liquid dielectric layer whose thickness may be continuously varied. The observed angular SHG spectra resulting from excitation of the coupled fundamental surface-plasmon modes are in reasonable agreement with a multilayer plane-wave theory. In contrast to the highly resonant SHG associated with the familiar long-range surface-plasmon mode, here the coupling of the surface modes decreases the SHG resonance because of the lossy nature of these new coupled modes.
© 1999 Optical Society of America
Qin Chen, X. Sun, I. R. Coddington, D. A. Goetz, and H. J. Simon, "Reflected second-harmonic generation with coupled surface-plasmon modes in Ag/liquid/Ag layers," J. Opt. Soc. Am. B 16, 971-975 (1999)