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Rare-earth-doped optical materials are important for light sources in optoelectronics, as well as for efficient optical amplification elements and other elements of photonics. On the basis of the previously developed method of anhydrous, low-temperature synthesis of Er/Yb oxides from their chlorides we fabricated proper nanoparticles with defined parameters and used them for the development of optically transparent, luminescent polymer nanocomposite with low optical scattering, suitable for direct, light-induced formation of photonic elements. Introduction of preformed gold nanoparticles in such a nanocomposite was also performed and an enhancement of luminescence due to the influence of plasmon effects was detected.

Patterning processes in amorphous Se and $$\hbox {As}_{20}\hbox {Se}_{80}$$ films at short electron beam pulses (from 200 ns to 100 ms) were studied for the first time. The surface reliefs occurring as after-pulses effects were recorded and analysed. Giant hillock formation was detected at about $$200\,\upmu \hbox {s}$$ pulses while very small changes in surface morphology were observed at other pulse durations. The obtained data indicate that the strong increase in e-beam sensitivity of mechanical response (giant surface hillock formation) at about $$200\,\upmu \hbox {s}$$ is due to some resonance effect. A qualitative description is given, relating these times to the characteristic generation and relaxation time of the defects in these materials, which illuminates the process of e-beam induced structural rearrangement. The measurement has been performed at room temperature and at $$-120\,^{\circ }\hbox {C}$$ and only a 20% change in the maximal pattern height has been detected.

In this work the performance of Au/Ag nanoislands was investigated for Surface Enhanced Raman Spectroscopy (SERS) and Localized Surface Plasmon Resonance (LSPR) applications. The nanoislands were generated by thermally annealing thin layers of silver and gold (having thickness in the 5-15 nm range), which were previously sputtered onto glass surfaces. Both pure (silver and gold nanoparticles – AuNP and AgNP) and composite metallic systems (silver-gold core-shell structures – Ag-Au core-shell) were evaluated based on their plasmonic and SERS sensitivity. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) were used to measure the size, shape and distribution of the nanoparticles to correlate them with the obtained plasmonic/Raman capabilities. The technological parameters of nanoisland fabrication for optimal sensitivities are presented.

Metal nanoparticle-semiconductor interfaces are sites of complex light-matter interactions, in particular, the exciton-plasmon coupling which plays a key role in the optical response of such heterostructures. There exists a pathway of photoinduced charge transfer from the semiconductor to the metal, which can be used to controllably vary the driving forces at the interface that leads to tunable optoelectronic properties. In this letter, we report the observation of a dramatic suppression of plasmonic as well as excitonic absorption in a-Ge24Se76/gold nanoparticle heterostructures by trapped charges. Suppression of the excitonic absorption is strongly correlated with the plasmon wavelength. (C) 2016 Author(s).

Parameters of photo-polymerization process (induction time, rate and degree of conversion) as well as the change of the refractive index, micro hardness and so of the resulting structure were investigated in urethane–acrylate based nanocomposites. Monomers were functionalized by adding SiO2 and Au nanoparticles by means of direct incorporation. The structural changes due to addition of nanoparticles and photo-polymerization were investigated by micro-Raman spectroscopy and X-ray diffraction (XRD). The real time changes in the refractive index due to irradiation were monitored by Surface Plasmon Resonance imaging (SPRi), which is a novel application of this platform. It is established that these nanoparticles have an influence on the polymer structure and on the transformation of selected bonds during the photo-polymerization process. The plasmon field of gold nanoparticles has a specific additional influence on these changes. These effects can be used to enhance surface relief recording in such nanocomposites due to the photo-stimulated mass transport of the nanoparticles embedded to the polymer matrix.

(Ag3AsS3)0.6(As2S3)0.4 thin films were deposited upon a quartz substrate by rapid thermal evaporation. Structural studies of the as-deposited, annealed and illuminated films were performed using XRD, scanning electron and atomic force microscopies. Surfaces of all the films were found to be covered with Ag-rich crystalline micrometer sized cones. Thermal annealing leads to mechanical deformation of part of the cones and their detachment from the base film surface while the laser illumination leads to the new formations appearance on the surface of thin films. The spectroscopic studies of optical transmission spectra for as-deposited, annealed and illuminated thin films were carried out. The optical absorption spectra in the region of its exponential behaviour were analysed, the dispersion dependences of refractive index as well as their variation after annealing and illumination were investigated.

Unusual profile variation of holographic surface relief gratings is detected in thin (2 μm) As20Se80 chalcogenide films under e-beam irradiation: gratings of small periods were smoothed, whereas the gratings of larger periods increased their amplitudes. Irradiation was carried out in SEM, with 20 kV voltage and 8 nA current; the profiles of the irradiated areas were analyzed both by AFM and SEM. It is found that the kinetics of both flattening and growth followed by exponential law and took place due to lateral mass transport accelerated by e-irradiation. It is shown that the profile variation is mainly caused by competition between capillary forces and “chemical” forces induced by broken and deformed atomic bonds under e-beam irradiation. The kinetics of profile variation was calculated assuming that the mechanism of e-beam induced mass transfer is volume diffusion. The diffusion coefficients were estimated from the experimental data using theoretical expressions derived.

Two types of amorphous materials with the same functional purpose – direct optical recording of optical amplitude–phase surface reliefs – were investigated with the aim to establish the influence of incorporated gold nanoparticles on the recording efficiency. It was shown that the laser recording of optical reliefs on the basis of photo-polymerization of the selected acrylates or on the basis of structural polymerization–destruction like processes in chalcogenides with photo-plastic effects can be enhanced in the presence of Au nanoparticles (AuNPs). The lateral mass-transport processes at the molecular and nanoparticle levels are initiated by the non-uniformly, periodically distributed recording optical fields and increase the resulting surface reliefs in these materials, which can be used as microstructured optical elements, holographic gratings.

Optical parameters of pristine As2S3 amorphous chalcogenide layers are compared with those of layer structures which consist of gold nanoparticles on silica glass substrate, covered by the layer of amorphous As2S3. The localized plasmon resonances are measured and modeled in dependence on the nanocomposite structure. It is shown, that plasmon fields can be excited in these structures by laser irradiation, complementing the action of light on this light sensitive chalcogenide glass and influencing structural transformations in the glass as well as changes of its optical parameters. The enhancement of the light stimulated changes of optical parameters used for laser recording of photonic structures in selected chalcogenide nanocomposites follows from the results.

We report the method of incorporation of preformed gold nanoparticles (AuNPs) into the acrylic polymer (AP) matrices and optical, TEM characterization of AuNP/AP bulk and film composite. It was shown that incorporation of dodecanethiol-covered AuNP can be enhanced in the presence of SiO2 nanoparticles, enabling at the same time a wider range of tailoring of composite properties for optical processing.

The technology problems of fabricating different, nanometers sized gold particles in the layered composites like light-sensitive chalcogenide glass/gold nanoparticles/transparent substrate or titanium/titanium oxide/gold nanoparticles were investigated in our work. Combination of ion implantation, plasma deposition with annealing processes results physical routes for creation of gold nanoparticles in the mentioned structures, which possess plasmon effects. These functionalized structures are planned to use for investigations of optical recording processes, biocompatibility of titanium implants.

© 2012 Denisyuk et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Optical Nanocomposites Based on High Nanoparticles Concentration and Its Holographic Application

Laser-matter coupling results specific structural changes in amorphous chalcogenide semiconductor layers which originate from electron-hole excitations, defect creation or modification and subsequent atomic motions. These changes can be influenced by plasmon fields. Plasmon enhanced photo-darkening and bleaching, optical recording in thin As x Se 1 − x films have been demonstrated in this paper, specifically in As 20 Se 80 and As 2 Se 3 compositions which revealed the best effects of stimulated expansion or optical darkening respectively due to the He–Ne laser (λ = 633 nm) illumination. Gold nanoparticles deposited on the silica glass substrate and covered by an amorphous chalcogenide film satisfy the conditions of efficient surface plasmon resonance in this spectral region. These experimental results support the importance of localized electric fields in photo-structural transformations of chalcogenide glasses as well as suggest better approaches for improving the performance of these optical recording media.

The role of the composition and of the related changes of the structure in the formation of the surface of amorphous As x Se 1− x (0 x x ⩽ 0.3, where the maximum light stimulated surface deformations (localized expansion) occurs. Both relate to the rigidity percolation range and the maximum photoplastic effects, which are not directly connected to the known photodarkening effect, since it is minimal for these compositions.

Cu 6 PS 5 X (X = I, Br) solid electrolytes are obtained in nanocrystalline state by ball milling, their crystalline structure is studied and average crystallite size is estimated from X-ray diffraction. Essential low-frequency shifts of Raman scattering bands, their broadening and intensity decrease with crystallite size decrease are observed. The specific features of Raman scattering in nanometric solid electrolytes are explained within the known approaches based on the results obtained and in comparison with the bulk crystals.

Cyclic pulsed laser deposition technique was used for the fabrication of chalcogenide GeSe/GeS nanomultilayers with ∼10 nm modulation period. Low-angle X-ray diffraction technique revealed good periodicity of prepared multilayered materials. The films are sensitive to annealing and illumination by 532 nm laser; both processes lead to refractive index decrease and blue shift of the short-wavelength absorption edge, respectively, connected with interdiffusion processes between the individual layers. Light-induced bleaching of the films is accompanied by giant volume-changes (up to 10% expansion) as observed by atomic force microscopy. These can be used for direct surface patterning and relief formation.

Investigations of $a-Se/As_2S_3$-type chalcogenide nanomultilayers (NML) were extended towards the metal-containing $Bi(Sb)/As_2S_3$ structures. It was shown that essential changes of optical parameters (transmission, refraction and reflection) and of the electrical conductivity occur due to the interdiffusion stimulated by direct heating or by the influence of the intensive laser beam unlike the chalcogenide–chalcogenide nanostructures, where the photo-induced effects may dominate. Low temperature solid-phase synthesis, phase separation can be performed this way. Stimulated structural changes in these multilayers may be used for efficient amplitude-phase modulated optical relief recording as well as for creating surface patterns with modified electrical parameters.

We have studied the nonlinear optical properties of nanolayered Se/As2S3 film with a modulation period of 10 nm and a total thickness of 1.15 mu m at two [1064 nm (8 ns) and 800 nm (20 ps)] wavelengths using the standard Z-scan technique. Three-photon absorption was observed at off-resonant excitation and saturation of two-photon absorption at quasiresonant excitation. The observation of the saturation of two-photon absorption is because the pulse duration is shorter than the thermalization time of the photocreated carriers in their bands and three-photon absorption is due to high excitation irradiance. (c) 2007 American Institute of Physics.

The effect of irradiation on the optical absorption edge and thickness of AsSe and As2S3 thin films has been investigated for different doses of 12H, 11H accelerated to energies of 80 and 180 keV. The kinetics and value of the stimulated changes were compared with photo-induced effects of laser illumination at 0.51 and 0.63 μm. It was observed that the optical band gap decreases and the thickness increases for both cases. The penetration length and depth profile of implanted ions with different energies were calculated and proposed for creating layer structures with depth-profiled optical parameters.