Second harmonic generation and broad-band photoluminescence in mesoporous Si/SiO nanoparticles.

Efficient second harmonic generation and broad-band photoluminescence from deeply subwavelength and nontoxic nanoparticles is essential for nanophotonic applications. Here, we explore nonlinear optical response from mesoporous Si/SiO, SiO, and Si nanoparticles, considering various fabrication and treatment procedures. We show that thermal annealing (including femtosecond laser treatment) of mesoporous Si/SiO nanoparticles provides the transformation of Si phase from amorphous to crystalline, enhancing the second harmonic and nonlinear photoluminescent response.

Modulation of GaAs nanowire growth by pre-treatment of Si substrate using a Ga focused ion beam.

We reveal a novel phenomenon observed after self-catalytic growth of GaAs nanowires (NWs) on Si(111) substrates treated with a Ga focused ion beam (FIB). Depending on the ion dose, NW arrays with various geometrical parameters can be obtained. A minor treatment of the substrate enables a slight increase in the surface density of NWs relative to an unmodified substrate area.

Elastic Gallium Phosphide Nanowire Optical Waveguides-Versatile Subwavelength Platform for Integrated Photonics.

Emerging technologies for integrated optical circuits demand novel approaches and materials. This includes a search for nanoscale waveguides that should satisfy criteria of high optical density, small cross-section, technological feasibility and structural perfection. All these criteria are met with self-assembled gallium phosphide (GaP) epitaxial nanowires.

Genetic Adaptation of Siberian Larch ( Ledeb.) to High Altitudes.

Forest trees growing in high altitude conditions offer a convenient model for studying adaptation processes. They are subject to a whole range of adverse factors that are likely to cause local adaptation and related genetic changes. Siberian larch ( Ledeb.