Metamaterials concept has been under extensive development over the past two decades and has been proven to be beneficial for a wide range of practical applications in both microwave and optical spectral ranges. In particular, it is commonly used for tailoring light-matter interactions on nanoscale. While many different approaches towards metamaterials fabrication exist, most of them are limited to “top-down” concept, including but not limited to lithographic methods, like photolithography, e-beam and nanoimprint lithography. On the other hand, the “bottom-up” chemical self-assembly techniques offer several distinctive advantages like throughput and cost-effectiveness, allowing large-scale production of composites. Here a novel metamaterial platform, based on mesoporous vaterite particles (further referred to as cargoes) is proposed and demonstrated. Controllable doping of micron and sub-micron scale dielectric hosts with metal nanoparticles enables tuning effective plasma frequency of new composites and, as the result, allows tailoring properties of collective localized plasmon resonances that they support. Furthermore, newly developed fabrication protocols enable introducing active materials (e.g. dyes and colloidal quantum dots) within vaterite cargoes and tailor their emission properties. Introduction of high concentration of active materials into compound particles allows compensating material losses in the medium with gain. Moreover, by coating the surface of the particles with passivating agents, it is possible to achieve long-term stability of such compound cargos in different types of solvents. Both unrestricted three-dimensional motion (compared to two-dimensional trapping of metallic particles) and rotation by circularly polarized trapping beams were demonstrated. Theoretical, numerical and experimental studies of those novel composites with beforehand mentioned properties will be presented. The vaterite-based metamaterial platform paves a way to new fundamental investigations and enables to introduce concepts of ultra-bright controllably floating imaging agents for relevant bio-medical applications.
We consider spatial hysteresis and modulational instability in arrays of nonlinear metallic nanoparticles. We show
that such plasmonic systems are characterized by a bistable response, and they can support the propagation of
dissipative switching waves (or plasmonic kinks) connecting the states with different polarization. We demonstrate
that modulational instability, also inherent in our system, can lead to the formation of regular periodic
or quasi-periodic modulations of the polarization. We reveal that arrays of metallic nanoparticles can support
nonlinear localized modes of two different types - plasmon-solitons and plasmon-oscillons. They both possess
deeply subwavelength size. However, the profile of plasmon-solitons is stationary; whereas plasmon-oscillons has
the oscillating profile which can stand at rest or slowly drift along the chain.
We show that metamaterial constituted from periodic array of identical noble-metal binary nanoparticles embedded into
dielectric host matrix can exhibit left-handed properties in optical frequency domain. In contrast to recent suggestions to
use, for example, double periodic lattice of metal nanowires or lattice of nanoparticle loops (or necklaces) binarynanoparticle
material utilizes lowest plasmonic eigenmodes (dipole and quadropole) providing necessary electric and
magnetic responses in the system of binary particles. This makes possible to extend negative refraction region due to
increasing of the corresponding resonances quality-factors in comparison to high multipole modes excited in nanoparticle
necklaces. Using the well-known optical constants for noble metals we calculate the optical response of binary-particle
metamaterials for silver, gold and copper in the wavelength range 350-1200nm. We find that silver is the most suitable
material for the particles which provides left-handed properties of metamaterial for approximately 400-1100nm
wavelengths (at different values of permittivity of the host) whereas the gold particles can lead to the negative refraction
only in more narrow range 750-1100nm because of the greater losses in the particles. Copper nanoparticle array seems to
be unable to produce left-handed metamaterial at all.