M. Mayy

Stimulated emission of surface plasmon polaritons

We have observed stimulated emission of surface plasmon polaritons (SPPs) propagating at the interface between a silver film and a film of optically pumped polymethyl methacrylate (PMMA) doped with rhodamine 6G (R6G) dye.

Controlling spontaneous emission with metamaterials

We have observed, in metamaterial with hyperbolic dispersion (an array of silver nanowires in alumina membrane), a sixfold reduction of the emission lifetime of dye deposited onto the metamaterials surface. This serves as evidence of an anomalously high density of photonic states in hyperbolic metamaterials, demonstrates the feasibility of an earlier-predicted single-photon gun, and paves the road for the use of metamaterials in quantum optics.

Engineering of low-loss metal for nanoplasmonic and metamaterials applications

We have shown that alloying a noble metal (gold) with another metal (cadmium), which can contribute two electrons per atom to a free electron gas, can significantly improve the metal’s optical properties in certain wavelength ranges and make them worse in the other parts of the spectrum. In particular, in the gold-cadmium alloy we have demonstrated a significant expansion of the spectral range of metallic reflectance to shorter wavelengths. The experimental results and the predictions of the first principles theory demonstrate an opportunity for the improvement and optimization of low-loss metals for nanoplasmonic and metamaterials applications.

Elongation of surface plasmon polariton propagation length without gain

We have demonstrated that an addition of highly concentrated rhodamine 6G chloride dye to the PMMA film adjacent to a silver film can cause 30% elongation of the propagation length of surface Plasmon polaritons (SPPs). The possibility to elongate the SPP propagation length without optical gain opens a new technological dimension to low-loss nanoplasmonic and metamaterials.

Low temperature studies of surface plasmon polaritons in silver films

We have studied propagation of surface plasmon polaritons at cryogenic temperatures and found the temperature-dependent optical loss reduction to be modest. Large temperature-independent components of the dc resistivity and the imaginary part of the dielectric constant at optical frequency are due to scattering on bulk and surface defects rather than on phonons. This suggests that the quality of metal should be improved first, after which a further improvement can be sought through the reduction of temperature.

Toward curvilinear metamaterials based on silver-filled alumina templates [Invited]

The method of fabrication of bulk three-dimensional curvilinear metamaterials based on metallic nanowires grown in porous alumina membranes was developed. Morphologically, fabricated structures resemble those earlier proposed for the design of an optical cloak and a hyperlens. Feasibility and flexibility of the suggested technological platform paws the road to engineering novel curvilinear hyperbolic metamaterials via inexpensive non-lithographic routes.

Development of composite silver-polymer metamaterials

We have synthesized and studied a series of composite silver-polymer photonic metamaterials with composition-tunable electric response. The dielectric constants of metamaterials, derived from the transmittance and reflectance spectra, were compared against several effective medium models. The demonstrated value of the real part of the dielectric constant e′=12.8 at λ=2.4 μm is one of the highest in the near-to-midinfrared spectral range.

Toward parametric amplification in plasmonic systems: second harmonic generation enhanced by surface plasmon polaritons.

Having in mind parametric amplification of surface plasmon polaritons (SPPs) as the final goal, we took the first step and studied in the Kretschmann geometry a simpler nonlinear optical process - second harmonic generation (SHG) enhanced by SPPs propagating at the interface between gold film and 2-methyl-4-nitroaniline (MNA). The experimentally demonstrated SHG efficiency was nearly 10(6) times larger than the one reported previously in the SPP system with different nonlinear optical material. The experimentally measured nonlinear conversion efficiency is estimated to be sufficient for parametric amplification of surface plasmon polaritons at ultra-short laser pumping.

Compensation of loss in propagating surface plasmon by optical gain

We experimentally demonstrate ~30% elongation of the surface plasmon propagation length and show that the full compensation of the surface plasmon loss by optical gain is within the reach.

Control of Emission and Reflection with Hyperbolic Metamaterials

As metamaterials with hyperbolic dispersion strongly modify the density of photonic states, they can be used for control of spontaneous emission and reflection as well as, potentially, a variety of other optical phenomena.