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Due to losses in metals, the propagation length of the surface plasmon-polariton (SPP) waves on metal surfaces is small. This severely limits development of numerous applications of the SPP optics: in the near-infrared spectral region propagation length of SPP waves is no longer than 200 μm as for plane SPP waves and for all types of SPP waveguides. In this work, we show that the focusing of SPPs allows for the first time realizing open-type waveguide for SPP waves characterized by long distance of SPP effective propagation length up to 1 mm at a wavelength of 780 nm. We show that focused SPP waves in such a waveguide can be effectively excited by a 16 fs laser as well as be amplitude modulated within a bandwidth about 3.5 THz. The fast dynamics of the focused SPP waves is limited by the SPP group velocity dispersion. The large effective propagation length of the SPPs and its ultra-high bandwidth open up new possibilities for using focused SPPs in different areas of plasmonics and photonics.

A single-layer atom chip for laser cooling and trapping of atoms which operates in a continuous regime is designed and experimentally investigated. The continuous regime was achieved by optimizing the processes of heat released and heat removal from the working area of the atom chip. To do this, we use silver microwires and optimization of the heat dissipation through different heat removal channels. The main channels for heat dissipation are the contacts of the silicon substrate of the atom chip with a copper massive base and the heat sink through the clamps. The design of the atom chip ensures efficient heat transfer from the work area to the periphery through the metal layer of the atom chip. Using continuous operation regime, we cooled and trapped about 3 ∙ 105 atoms near the atom chip.

Anomalous optical response for the metamaterial fabricated from silicon bar resonators is investigated. The resonators are manufactured in form of two-dimensional bars and covered by semicontinuous silver film. The calculations as well as real experiments demonstrate Wood anomalies in visible and near IR spectral ranges associated with excitation of the surface waves in metamaterial by means of diffraction of the incident light on the periodic bars. The multiple metal-dielectric resonances result in much enhanced local electromagnetic fields in-between metal particles placed on the surface of dielectric bars. The resonances can be tuned by varying angle of incidence, polarization, and geometry of the dielectric bars. It opens new venue in R&D SERS substrates including sensors detecting specific substances.

Observation of the wanted Raman signal from SERS substrates is hampered by the background luminescence. We investigate the metasurface made of periodic silicon micro bars with thin silver layer on the top. The computer simulations as well as real experiment reveal the anomalous optical response of the metasurface is due to the excitation of the metal-dielectric surface resonances. We demonstrate the enhanced Raman signal from the organic molecules of 5,5-dithio-bis[2-nitrobenzoic] acid deposited on the microbar metasurface. The microbar metasurface exhibits large Raman/luminescence (signal/noise) ratio. As result it operates as an efficient SERS substrate.

Optical properties of two-dimensional periodic systems of the dielectric micro bars and micro cones are investigated. Computer simulations as well as real experiment reveal anomalous optical response of the dielectric metasurface due to excitation of the dielectric and metal-dielectric resonances, which are excited in-between metal nanoparticles and dielectric cones and bars. In the metal-dielectric resonance local electric field can be orders on magnitude larger than the field in the plasmon resonance only. To investigate local electric field the signal molecules were deposited on the metal nanoparticles. We demonstrate the enhancement of the electro- magnetic field by detecting the Raman signal from the of organic acid molecules deposited on the investigated metasurface.

We demonstrate the optical medium for surface plasmon-polariton wave (SPP) propagation with ultra low losses corresponding to the theoretically limited values. The unique element of the optical medium is an atomically-flat single-crystalline silver thin film that provides extremely low losses. The SPP excited on the surface of such thin films (λ = 780 nm) is characterized by a SPP propagation length equal to 200 µm, which is twice longer than previously reported experimental results and corresponds to theoretically limited values for silver films.