Functionalization of Phosphate and Tellurite Glasses and Spherical Whispering Gallery Mode Microresonators.

Active whispering gallery mode resonators made as spherical microspheres doped with quantum dots or rare earth ions achieve high quality factors and are excellent candidates for biosensors capable of detecting biomolecules at low concentrations. However, to produce quantum dot-doped microspheres, new low melting temperature glasses are sought, which require surface functionalization and antibody immobilization for biosensor development. Here, we demonstrate the successful functionalization of three low melting point glasses and microspheres made of them.

Surprising Eutectics: Enhanced Properties of ZnO-ZnWO from Visible to MIR.

Zinc oxide-zinc tungstate (ZnO-ZnWO ) is a self-organized eutectic composite consisting of parallel ZnO thin layers (lamellae) embedded in a dielectric ZnWO matrix. The electromagnetic behavior of composite materials is affected not only by the properties of single constituent materials but also by their reciprocal geometrical micro-/nano-structurization, as in the case of ZnO-ZnWO . The light interacting with microscopic structural features in the composite material provides new optical properties, which overcome the possibilities offered by the constituent materials.

Compendium of natural hyperbolic materials.

Artificially structured hyperbolic metamaterials (HMMs) - uniaxial materials with opposite signs of permittivity for ordinary and extraordinary waves - are one of the most attractive classes of metamaterials. Their existing in nature counterpart natural (homogeneous) hyperbolic materials (NHMs) has several advantages but has not yet been analyzed extensively. Here, based on literature-available data on permittivity as a function of wavelength, we review materials with naturally occurring anisotropy of permittivity in specific wavelength ranges.

Interacting plasmon and phonon polaritons in aligned nano- and microwires.

The availability of macroscopic, nearly periodic structures known as eutectics opens a new path for controlling light at wavelength scales determined by the geometrical parameters of these materials and the intrinsic properties of their component phases. Here, we analyze the optical waveguiding properties of eutectic mixtures of alkali halides, formed by close-packed arrangements of aligned cylindrical inclusions. The wavelengths of phonon polaritons in these constituents are conveniently situated in the infrared and are slightly larger than the diameter and separation of the inclusions, typically consisting on single-crystal wires down to submicrometer diameter.

Structure of YAG crystals doped/substituted with erbium and ytterbium.

Two series of yttrium aluminum garnets doped with erbium and ytterbium ions have been studied by single-crystal X-ray diffraction. The single crystals were obtained by the Czochralski method. The concentration of doping ions was established by the plasma emission spectroscopy method.