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The realization of crystalline sub micrometric films of Nd 3+ :LiYF 4 fluorides on pure LiYF 4 substrates by pulsed laser deposition is reported. The films were obtained by laser ablation with 355 nm photons of a bulk LiYF 4 crystal doped with Nd 3+ ions at 1.5% atomic concentration. Both low and high laser ablation fluency regimes were checked. The fundamental contribution of He inside a vacuum chamber to obtain crystalline Nd 3+ :LiYF 4 films was demonstrated. The optical characteristics of the films were analyzed via recording the emission spectra following IR excitation, polarized both with E II and E ⊥ to the substrate c-axis. Lifetime measurements of the fundamental Nd 3+ ion transition in the films were also performed. All the results were compared with those obtained in the Nd 3+ :LiYF 4 bulk crystal under the same experimental conditions. The scanning electron microscope pictures of the depositions gave indications about the film surface morphology.

The realization of crystalline films of Nd3+:YF3 and Nd3+: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 Nd3+ 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 Nd3+: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 Nd3+:YF3. A 1 Pa controlled atmosphere of He in the ablation chamber and a substrate temperature of 650 °C favoured the growth of a Nd3+:LiYF4 film. In the latter case the film showed also a smoother surface.

The spectroscopy of dense Ga, In and In–Ga vapours is studied via resonant pulsed laser excitation at 403.4 nm (Ga) and 410.3 nm (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.

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≅10 13 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.

The availability of recombinant human growth hormone (GH) and the optimization of substitutive therapy have improved final growth in children with GH deficiency, but despite this some of them fail to grow to their genetic potential. In particular, this may occur in patients who started the substitutive therapy too late and/or in whom bone age progressed too fast during GH administration. In these patients, with unfavorable auxological characteristics, the administration of a GnRH agonist in combination with GH may slow down bone maturation and prolong prepubertal growth, mimicking, to some extent, the growth pattern of patients with GH + Gn deficiency who grow better than children with isolated GHD. A different condition in which such a combined therapy might be used is the short normal child. As they are short but normally-growing children, the onset of puberty is in general appropriate for their chronological age but precocious for their height age. Thus, slowing down pubertal maturation may increase the time available for growth. GH would sustain growth during both GnRHa administration and after its withdrawal, when puberty starts again. Our preliminary results suggest that the administration of GH + GnRHa in combination may have a positive effect on final height in selected children with isolated GHD and in short normal children.