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Copper–alkali ion exchange is used for doping superficial layers of different silicate glasses (commercial soda-lime and BK7) with copper ions. Spectroscopic and time-resolved photoluminescence properties of the obtained systems are studied in the range of 80–294 K. Analysis indicates the presence of Cu+ ions located in distorted octahedral sites, and a different position of the triplet electronic levels for the two glass matrices. The luminescence decay-time signal is simulated by a biexponential behavior, interpreted on the basis of a four-level scheme

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GaN nanocrystals (in the wurtzite phase) were synthesized by sequential implantation of Ga and N ions into either crystalline (quartz, sapphire) or amorphous (silica) dielectrics, followed by annealing of the samples in flowing NH3 gas at 900 degreesC. GaN was formed by reaction of implanted Ga with NH3 combustion products and/or via conversion of Ga oxide/oxynitrides. A blueshift of the near-band-edge photoluminescence (quantum-confinement effect) was observed for GaN nanocrystals with size less than or equal to2-3 nm, present in all the substrates

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We determined the third-order susceptibility |χ (3) | of a thin composite film formed by silver nanoclusters embedded in soda-lime glass. Ag aggregation was promoted by irradiating an Ag-Na ion-exchanged glass with an N + beam. |χ (3) | dispersion was measured by phasemismatched degenerate four-wave mixing in the 380-470 nm spectral range, with 0.5 ps laser pulse duration. Close to the surface plasmon resonance of Ag metallic clusters, the χ (3) amplitude exceeds by a factor of 10 4 the value of substrate glass. We also measured a phase of 83 • and a dynamics characterized by ∼ 30, 3 and 0.9 ps decay times, ascribed to hot-electrons-lattice thermalization in the clusters, followed by thermal diffusion toward the matrix and relaxation of the whole system to the starting temperature.

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