New trends in femtosecond Pulsed Laser Deposition and femtosecond produced plasma diagnostics

International audienceThe availability of compact table top amplified femtosecond lasers and the technical simplicity of experimental design have opened the way to many recent and fast developments towards thin film elaboration by Pulsed Laser Deposition (PLD) with ultra short laser pulses, with the aim of producing materials of high quality previously unattainable or attainable only through more complex means. The first developments of PLD using femtosecond lasers were made on Diamond-Like Carbon thin films elaboration, with the attempt to reach high sp3 content. PLD with ultra short pulses was used recently to deposit several systems such as quasicrystals or oxides with a transfer of the target composition to the deposited films, even for compounds with complex stoechiometry. Femtosecond laser ablation from solid targets has shown its capability in producing nanoparticles of different materials, even in high vacuum conditions. Nanostructured films of doped Diamond-Like Carbon were obtained recently, opening the way to large applications towards functional materials. The characteristics of the plasma are a well-suited signature of the physics of laser-matter interaction and plasma plume creation and expansion. Recent studies on the control of the film growth and femtosecond PLD processes will be reported. Emphasis on actual capability of the existing sources to elaborate high quality materials will be questioned in terms of energy per pulse, time width, repetition rates but also in the need for further source development and beam shaping improvement

Do patients have to choose between ejaculation and miction? A systematic review about ejaculation preservation technics for benign prostatic obstruction surgical treatment

PURPOSE: Ejaculatory dysfunction is the most common side effect related to surgical treatment of benign prostatic obstruction (BPO). Nowadays, modified surgical techniques and non-ablative techniques have emerged with the aim of preserving antegrade ejaculation. Our objective was to conduce a systematic review of the literature regarding efficacy on ejaculatory preservation of modified endoscopic surgical techniques, and mini-invasive non-ablatives techniques for BPO management. METHODS: A systematic review of the literature was carried out on the PubMed database using the following MESH terms: "Prostatic Hyperplasia/surgery" and "Ejaculation", in combination with the following keywords: "ejaculation preservation", "photoselective vaporization of the prostate", "photoselective vapo-enucleation of the prostate", "holmium laser enucleation of the prostate", "thulium laser", "prostatic artery embolization", "urolift", "rezum", and "aquablation". RESULTS: The ejaculation preservation rate of modified-TURP ranged from 66 to 91%. The ejaculation preservation rate of modified-prostate photo-vaporization ranged from 87 to 96%. The only high level of evidence studies available compared prostatic urethral lift (PUL) and aquablation versus regular TURP in prospective randomized-controlled trials. The ejaculation preservation rate of either PUL or aquablation compared to regular TURP was 100 and 90 versus 34%, respectively. CONCLUSIONS: Non-ablative therapies and modified endoscopic surgical techniques seemed to be reasonable options for patients eager to preserve their ejaculatory functions

Optical properties of nickel-incorporated amorphous carbon film deposited by femtosecond pulsed laser ablation

International audienceThe present study investigates the optical properties of Ni-incorporated amorphous carbon (a-C:Ni) films covering a wide range of Ni concentration from doping to alloys. The films are deposited by sequential femtosecond pulsed laser ablation of graphite and Ni targets. The optical properties are analyzed by means of the Maxwell-Garnett theory with separated metal and carbon phases. This analysis permits to investigate the change of the carbon phase with Ni concentration. It is shown that the microstructure of the carbon phase is affected by the Ni incorporation even at low Ni concentrations (1 at.%) where a local reorganization of the carbon matrix occurs affecting the aromatic clusters. At higher Ni concentrations the films become more disordered

Optical, electrical and structural investigations of nanostructured coatings of metal-incorporated amorphous carbon

The structure and physical properties of nano-structured metal (nickel and tantalum) incorporated amorphous carbon (a-C:Ni and a-C:Ta) thin films deposited by femtosecond pulsed laser deposition (PLD) have been investigated. Various complementary film characterizations, including atomic force microscopy (AFM), Fourier-transform infrared spectroscopy have been used to determine the nanostructure of the a-C :Ni and a-C :Ta films, with a metal concentration range within 1% and 15 at.%. The electronic and optical properties have been also investigated in order to evaluate the potentialities of the coatings consisting in metallic nodules embedded in an amorphous carbonaceous matrix. The influence of the metal nature and concentration on the structure and properties of the films has been highlighted. The ability of femtosecond pulsed laser deposition to synthesize nanocomposite carbon-based films with tailored structures and properties is discussed

Nanocomposite tantalum–carbon-based films deposited by femtosecond pulsed laser ablation

International audienceNanostructured coatings of metal (tantalum) containing diamond-like carbon (a-C:Ta) have been prepared by femtosecond pulsed laser deposition (PLD). The films, containing 15 at.% tantalum, have been deposited by ablating sequentially graphite and metallic tantalum in vacuum conditions with an amplified Ti:sapphire laser. The coatings have been investigated by X-ray photoelectron spectroscopy, grazing angle X-ray diffraction, energy filtered transmission electron microscopy, scanning and high resolution transmission electron microscopies. Evidence of metallic α-Ta and β-Ta particles (diameter in the 100 nm range) and smaller quasi-amorphous tantalum clusters embedded in the carbonaceous matrix have been shown. A thin tantalum carbide interface between the carbon matrix and the top surface of the tantalum nodules has also been identified. The ability of femtosecond pulsed laser deposition to synthetize nanocomposite carbon-based films and to control their nanostructure is discussed

Nano-stucrured coatings of metal containing Diamond-Like Carbon films deposited by femtosecond pulsed laser ablation

International audienceNanocrystallized metal (Me)/carbon-based films (a-C:Me) have been deposited by femtosecond pulsed laser ablation (PLD). The films have been obtained by ablating alternatively and sequentially graphite and metallic targets in vacuum conditions, with an amplified femtosecond Ti:sapphire laser (wavelength 800 nm, pulsed duration of 150 fs). The metals selected, regarding of their opposite chemical affinity with carbon, are nickel and tantalum. The deposition procedure allowed to control accurately the metal concentration introduced in the carbonaceous matrix, in the 15 at.% range. The composition and nanostructure of the films have been characterized by X-ray photoelectron spectroscopy, grazing incident angle X-ray diffraction and energy filtered transmission electron microscopy. The nanocomposite coatings contain metallic clusters in the 10–250 nm size range, embedded in the carbonaceous network. The interface between the metallic clusters and the carbon matrix depends on the chemical affinity of the metal in respect to carbon