Multi-Frequency Light Sources Based on CVD Diamond Matrices with a Mix of SiV and GeV Color Centers and Tungsten Complexes.

Recently, nanodiamonds with negatively charged luminescent color centers based on atoms of the fourth group (SiV, GeV) have been proposed for use as biocompatible luminescent markers. Further improvement of the functionality of such systems by expanding the frequencies of the emission can be achieved by the additional formation of luminescent tungsten complexes in the diamond matrix. This paper reports the creation of diamond matrices by a hot filament chemical vapor deposition method, containing combinations of luminescing Si-V and Ge-V color centers and tungsten complexes.

Duo Emission of CVD Nanodiamonds Doped by SiV and GeV Color Centers: Effects of Growth Conditions.

The investigation of the hot filament chemical vapor deposition nanodiamonds with simultaneously embedded luminescent GeV and SiV color centers from solid sources showed that both the absolute and relative intensities of their zero-phonon lines (at 602 and 738 nm) depend on nanodiamond growth conditions (a methane concentration in the CH/H gas mixture, growth temperature, and time). It is shown that a controlled choice of parameters of hot filament chemical vapor deposition synthesis makes it possible to select the optimal synthesis conditions for tailoring bicolor fluorescence nanodiamond labels for imaging biological systems.

Effect of Reactive Ion Etching on the Luminescence of GeV Color Centers in CVD Diamond Nanocrystals.

The negatively charged germanium-vacancy GeV color centers in diamond nanocrystals are solid-state photon emitters suited for quantum information technologies, bio-sensing, and labeling applications. Due to the small Huang-Rhys factor, the GeV-center zero-phonon line emission is expected to be very intensive and spectrally narrow. However, structural defects and the inhomogeneous distribution of local strains in the nanodiamonds result in the essential broadening of the ZPL.

Low-strain heteroepitaxial nanodiamonds: fabrication and photoluminescence of silicon-vacancy colour centres.

Nanodiamonds with the 'diamond' 1332.5 cm(-1) Raman line as narrow as 1.8 cm(-1) have been produced by reactive ion etching in oxygen plasma of heteroepitaxial diamond particles grown by microwave plasma enhanced chemical vapour deposition (MWPECVD) on silicon.

Filtering of elastic waves by opal-based hypersonic crystal.

We report experiments in which high quality silica opal films are used as three-dimensional hypersonic crystals in the 10 GHz range. Controlled sintering of these structures leads to well-defined elastic bonding between the submicrometer-sized silica spheres, due to which a band structure for elastic waves is formed. The sonic crystal properties are studied by injection of a broadband elastic wave packet with a femtosecond laser.