Nonlinear surface polaritons

J. E. Sipe and G. I. Stegeman, Nonlinear Optical Response of Metal Surfaces. In Surface Polaritons Electromagnetic Waves at Surfaces and Interfaces, M. Agranovich and L. Mills, Eds., Elsevier, Amsterdam, 1982. 

In the experimental study of surface excitons various optical methods have been used successfully, including the methods of linear and nonlinear spectroscopy of surface polaritons. A particularly large body of information has been obtained by the method of attenuated total reflection of light (ATR), introduced by Otto (1 2) (Fig. 12.1) to study surface plasmons in metals. Later the useful modification of ATR method also was introduced by Kretschmann (3) (the so-called Kretschmann configuration, see Fig. 12.2). The different modification of ATR method has opened the way to an important development in the optical studies of surface waves and later was used by numerous authors for investigations of various surface excitations. 

During 1980-1981 the possibility of the existence of nonlinear surface polaritons of various types was predicted in the literature (18), (19)-(20). In particular, Tomlinson (19) and Maradudin (21) derived s-polarized surface polaritons at a plane interface between two dielectrics, one of which has an isotropic and linear (e1) dielectric constant whereas the dielectric constant of the other is that of a nonlinear uniaxial medium... 

Nonlinear p-polarized polaritons for b = 0 were considered under the same conditions (20). The papers cited revealed the dispersion laws of nonlinear waves of s and p types. Their most significant features are the non-monotonic dependence of the field amplitudes on z and the dependence of the frequencies of these waves on the field amplitude at the boundary (i.e. at z = 0). We do not go into details of the calculations here. We emphasize only that the transition layer, which can also be optically nonlinear, was ignored in these papers. Taking into account the nonlinearity in the transition layer results in the dependence of surface wave characteristics on the field at the interface, and this special case has been dealt with (22), (23) in connection with the problem of self-focusing of surface polaritons. 

During this time period, several groups investigated the SH response from metallic films using attenuated total reflection techniques (ATR) in which the nonlinear response is enhanced by coupling into surface plasmons (or polaritons) [28-38]. Simon et al. [28] were the first to demonstrate this effect. 

Collective optical excitations, like surface plasmon-polaritons in partially-ordered metal nanoparticle arrays, tend to be spatially localized. The localization facilitates a giant increase of linear and nonlinear optical responses such as Raman scattering, enhancement of spontaneous emission rate, nonlinear absorption and refraction. In this paper the spectral manifestation of light localization into metal-dielectric nanocomposites i s s tudied i n t he visible. T he e ffect o f t he 1 ateral e lectrodynamic coupling on transmission/reflection optical spectra is investigated for planar silver nanoparticle arrays (random close-packed and polycrystalline quasiregular structures). Combined action of electron and photon confinements is demonstrated experimentally and considered theoretically for ID-photonic crystals consisted of a metal nanoparticle stratified array. 

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