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Abstract: The realization of crystalline films of Nd 3+ :YF3 and Nd 3+ :LiYF4 on a monocrystalline LiYF4 substrate by pulsed laser deposition is reported. The films were obtained by laser ablation with 355 nm photons of a bulk LiYF4 crystal doped with Nd 3+ ions at 1.5% atomic concentration in the presence of different ablation/deposition parameters. The films optical characteristics, analyzed via laser induced polarized fluorescence spectroscopy upon IR excitation, are presented. Lifetime measurements of the fundamental Nd3+ ion transition in the film were also performed. All these results were compared with those obtained in the Nd 3+ :LiYF4 bulk crystal. The surface morphology of the depositions was analyzed via a scanning electron microscope. When the production of the deposition took place in high vacuum (1×10−4 Pa) and the substrate temperature was 750 °C, the grown film was Nd 3+ :YF3. A 1 Pa controlled atmosphere of He in the ablation chamber and a substrate temperature of 650 °C favoured the growth of a Nd 3+ :LiYF4 film. In the latter case the film showed also a smoother surface. [Copyright &y& Elsevier]

Abstract: The realization of a monocrystalline nanofilm of Nd3+-doped fluoride on LiYF4 substrates by pulsed laser deposition is reported. The film was obtained by laser ablation with 355 nm photons of a bulk LiYF4 crystal doped with Nd3+ ions at 1.5% atomic concentration. The measurements of the sample thickness obtained by an in situ interferometric technique, and the film optical characteristics analyzed via laser induced fluorescence spectroscopy upon UV and IR excitation, are presented. Lifetime measurements of the fundamental Nd3+ ion transition in the film were also performed. All the results were compared with those obtained in a Nd3+:LiYF4 bulk crystal. The emission spectra of the deposited film following IR excitation seem to indicate the obtained deposit is Nd3+:YF3. [Copyright &y& Elsevier]

Abstract: We show how the interaction between Ga atoms and silica samples in a hot environment gives rise to permanent inclusions of Ga inside the silica matrix which, in turn, produce typical luminescence features. The Ga doped silica is analyzed via laser induced fluorescence, photoluminescence and electron paramagnetic resonance spectroscopies. The results evidence the presence of modifications induced by the Ga inclusions inside the silica matrix and some preliminary hypothesis on their nature are advanced. Possible applications of such Ga doped silica are also mentioned. [Copyright &y& Elsevier]

Abstract: We performed temporal as well as frequency-resolved emission spectroscopy of the plasma plume generated in vacuum by 355nm pulsed laser ablation of a LiYF4:Tm3+ crystal (1% Tm3+ concentration) and a LiYF4:Nd3+ crystal (1.5% Nd3+ concentration). The plume emission spectrum is very rich in features and shows the elemental lines belonging to all the components of the host lattice, either neutral or ionized. The time-resolved analysis of some emission features is discussed and some stream velocities are derived. A possible model for the time evolution of the plume components is reported. The electronic detection technique was used to detect the onset of the plasma plume and to measure the ablation laser fluence threshold. [Copyright &y& Elsevier]

Abstract: We present the first spectroscopical analysis of the Ga/SiO2 surface interaction in hot environment. This interaction gives rise to inclusions of Ga atoms inside the silica matrix that produce structural changes and modify the SiO2 optical characteristics. This paper discusses both the time- and the frequency-resolved spectra of the fluorescence emission following UV pulsed laser excitation of the so “doped” silica in the range 15,000–28,000cm−1. The investigation is completed by the electron paramagnetic resonance (EPR) spectra of two high-purity synthetic silica samples of commercial origin after thermal treatment in presence and in absence of a Ga atmosphere. [Copyright &y& Elsevier]

Abstract: The spectroscopy of dense Ga, In and In–Ga vapours is studied via resonant pulsed laser excitation at 403.4nm (Ga) and 410.3nm (In). Besides some known atomic Rydberg levels emission, satellite wings on the blue side of the fundamental transitions show up both in the homonuclear and heteronuclear vapours. They are due to the presence of excited homonuclear dimers that form in the collision between excited and ground-state atoms. The formation of heteronuclear dimers is inferred by the time-resolved analysis of some atomic fluorescences. [Copyright &y& Elsevier]

This paper reports on the excitation of the nP→52S1/2 series, when Ga vapour inside a quartz cell, with or without buffer gas, at a temperature larger than 900°C, is resonantly excited by laser pulses at 403.3 nm corresponding to the 42P1/2→52S1/2 excitation. The analyses of the fluorescence intensities as a function of several different experimental parameters demonstrate the nP levels to be populated via energy-pooling ionisation. [Copyright &y& Elsevier]

We present the first results about the quenching of the radiation trapping in Ga vapour kept in a quartz cell when its temperature exceeds 1000°C, corresponding to an atomic density≅1013 cm−3. We show that this unusual behaviour is due, besides the energy-pooling ionisation effect, to the formation of fluorescent centres inside the quartz lattice in the interaction between Ga atoms and the fused silica structure. The first preliminary quantitative results are also reported. [Copyright &y& Elsevier]