Nonlinear Surface Plasmon Research Articles

Nonlinear Surface Plasmon Polaritons at the Interfaces Between Isotropic Media and Anisotropic Left-Handed Materials

Linear and nonlinear surface plasmon polaritons propagating along the interfaces between isotropic media and uniaxially anisotropic left-handed materials are investigated. A transition layer sandwiched between the connected media is described using a model of a two-dimensional gas of semiconductor quantum dots. The conditions of the existence of surface TM-modes when the components of the permittivity and permeability tensors of the anisotropic left-handed materials are simultaneously negative are determined. Explicit analytical expressions for a surface optical two- dimensional soliton of self-induced transparency in the presence of single and biexciton transitions are given. Numerical simulations for surface solitons are given for different layered systems. It is shown that the total energy flow of the surface solitons depends on the parameters of the quantum dots and the connected media.

Transverse instability of transverse-magnetic solitons and nonlinear surface plasmons

We analyze stability of the TM polarized optical solitons and nonlinear guided waves localized at a metal-dielectric interface. We demonstrate, both analytically and numerically, that the spatial solitons can experience vectorial transverse modulational instability that leads to the generation of arrays of two-dimensional TM polarized self-trapped localized beams. In a sharp contrast, we reveal that the transverse instability is completely eliminated for nonlinear surface plasmons.

Nonlinear Plasmonics

Theoretical and experimental results on laser light-excited nonlinear surface plasmon (SPO) phenomena are reported. Strongly directional light emission of SPOs was indicated and observed already at relatively low cw laser power. The width of this peaked directional distribution seems to depend on the laser power. Another manifestation of nonlinearity was found by observing a weak squeezing effect in the SPO-emitted fundamental light. At high (pulsed) laser intensity an evanescent (SPO) field enhanced second harmonic emission and a broad metallic luminescent spectrum was found. The second harmonic component is spectrally broader than the fundamental SPO-emitted light. Our simple theoretical model describes all of these observations qualitatively, except for the broad luminescent spectrum.

SPM of nonlinear surface plasmon waveguides

Pulse propagation equation of nonlinear dispersion surface plasmon waveguide is educed strictly from wave equation. The nonlinear coefficient is defined and then used to assess and compare the nonlinear characteristic of three popular 1-D surface plasmon waveguides: the single metal–dielectric interface, the metal slab bounded by dielectric and the dielectric slab bounded by metal. SPM (self-phase modulation) of the typical surface plasmon waveguide is predicted and discussed.

Nonlinear surface plasmon polaritonic crystals

AbstractWe present an overview of the optical properties of nonlinear surface plasmon polaritonic crystals and their applications to control light with light. Surface plasmon polaritonic crystals are periodically nanostructured metal surfaces or thin metal films that act as two‐dimensional photonic crystals for surface polaritons. Hybritization of such nanostructures with dielectrics exhibiting an optical nonlinear response allows utilization of the electromagnetic field enhancement effects to observe nonlinear effects and bistable behaviour at low light intensities. By changing the geometry of the nanostructured film, the dispersion of the crystal is modified and, thus, electromagnetic mode structure and associated density of states can be controllably tuned in the desired spectral range. This provides enhanced flexibility in engineering the nonlinear optical response of plasmonic crystals in a chosen spectral range for both control and signal wavelengths.

Time-resolved nonlinear surface plasmon optics

A new surface-sensitive method of time-resolved optical studies is proposed. The method consists in the independent excitation of several surface electromagnetic waves (SEW) by two laser femtosecond pulse beams with varied time delay Δτ and distance Δr between corresponding excitation regions on the surface. To fulfill the phase-matching condition for plasmon-photon coupling, metal grating is used. Due to nonlinear plasmon interaction, the optical radiation with ω1 + ω2 and 2ω1 − ω2 (where ω1, ω2 are corresponding laser beam frequencies) is generated. The intensity of this nonlinear response versus Δτ and Δr are studied. The direct measurements of the SEW temporal properties are presented. Experiments of this type are important for the development of femtosecond surface plasmon optics.

Nonlinear TM-polarized waves in non-kerr media

Both the dispersion relation and the guided power flow for nonlinear TM-polarized guided waves have been derived. These guided waves are allowed to propagate down a configuration where a linear film is sandwiched between two rather general nonlinear media as well as down a single interface that separates two nonlinear media. The analytical results have been found using first integrals of the wave equation instead of their explicit solutions. The power flow dependence of the propagation constant in saturable media is discussed numerically, for the cases of nonlinear surface plasmon polaritons and nonlinear surface polaritons as well as for long- and short-range surface plasmon polaritons.

Nonlinear TE-polarized surface plasmon polaritons guided by metal films

The power dependence of the wavevector is calculated for nonlinear TE-polarized surface plasmon polaritons guided by a thin metal film sandwiched between a linear substrate and a nonlinear cladding whose dielectric constant varies as any power of the optical field, and can be saturated.

Nonlinear surface plasmons guided by thin metal films

We have derived and solved numerically the dispersion relations for waves guided by a thin metal film bounded on one or both sides by media with intensity-dependent refractive indices. Depending on the conditions, the usual two modes can be cut off and can undergo radical changes in their field distributions, and new modes can exist above certain power threshholds.

Attenuated total reflection calculations for nonlinear surface plasmon dispersion

Nonlinear dispersion relations of surface plasmons are calculated in an attenuated total reflection (ATR) configuration using numerical techniques. Our results show that for the large field case, two surface plasmon branches exist for certain boundary conditions. The coupling conditions to the two branches are shown to be dependent on the initial conditions of the ATR system.