The behavior of spontaneous emission of emitters embedded inside metamaterials with hyperbolic dispersion has
been investigated. A simple technique has been developed to fabricate lamellar metal-dielectric hyperbolic
metamaterials on substrates which can be flat, flexible or curvilinear in geometry. Moreover, this method opens up the
possibility of functionalizing the dielectric layers by dye molecules. Utilizing this technique, we study the spontaneous
emission kinetics of emitters placed either on top, or embedded inside hyperbolic metamaterials. While we observe a
reduction in the radiative lifetimes in both cases, owing to the singularity in the density of photonic states, the effect is
much stronger when the dye molecules are inside the metamaterial, rather than on its surface.
We discuss major factors responsible for obtaining transparent Nd3+:YAG ceramic, a prospective material for laser
applications. The relationship between the properties of starting nanopowders and the transmittance of specimens
sintered at the different "ramp-soak" conditions was established by means of spectroscopic, structural, and electronic
microscopy studies. It was found, that sample's transmittance (in some cases) depends on the duration of the holding
time at the sintering stage. This result is promising for obtaining laser quality materials. It also contributes to basic
understanding of the processes underlying fabrication of transparent laser ceramic.
In this paper several approaches to fabricate semiconductor magnetic nanocomposite are reported. Several thiol- and amino- silane cross linked molecules were used to couple and embed CdSe and Fe3O4 nanoparticles into silica particles. The resulting nanocomposites were characterized by optical spectroscopies, transmission electron microscopy, electron paramagnetic spectroscopy and fluorescence optical microscopy. The new developed nanocomposite particles posses the advantage of being both magnetic and luminescent. The chemical functionality rich surface of these new nanoparticles could enable their application in bioassays, cell separation and drug delivery.
Clusters of CdS were prepared inside the framework voids of zeolites NaX and chabazite by multistage ion exchange chemical reaction. It was observed that each stage of reaction affects the structure of zeolites crystals. Aluminum atoms change their coordination state at the first stage because of hydrolytic decomposition of some Al-O tetrahedral bonds. Partially reversible relaxation of aluminum atoms of zeolite framework occurs during the second stage of chemical reaction. This spontaneous transition of the coordination number of aluminum atoms took place without changing of their positions of framework atoms. Such kind of the interaction between framework atoms of alumosilicates and doping ions, which are precursors of the clusters in the zeolite hosts, give indirect information about mechanism of the `ship-in-the-bottle' synthesis of semiconductor materials.