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Abstract: Femtosecond laser micromachining of a Zr-based amorphous alloy in air, including measuring the ablation threshold, micro-drilling and trenching, was investigated. The threshold of ablating this amorphous alloy was determined by experiment. Laser-induced ablation and associated damage were examined by means of optical microscope, scanning electron microscopy, transmission electron microscopy and electron diffraction diagram. The results show that conventional processing method induced defects in the vicinity of machined area, such as crystallization, molten trace and spatter, were absent in femtosecond laser ablation area with selected parameters. This indicates that femtosecond laser ablation is a promising method for micromachining amorphous alloys without crystallization. [Copyright &y& Elsevier]

Ga-doped zinc oxide (GZO) nano-triangle arrays with different doping concentration and sizes were fabricated by nanosphere lithography (NSL) and pulsed laser deposition (PLD) techniques, using GZO targets and polystyrene (PS) spheres. The influences of doping concentration on band gap and optical properties were investigated using ultraviolet-visible spectra and Fourier transform infrared (FTIR) spectra. The surface plasmonic resonance (SPR) peaks of the GZO nano-triangle arrays could be tuned in infrared region by changing the doping concentration. The surface-enhanced infrared spectroscopy (SEIRS) experiments of polymethyl methacrylate (PMMA) films on GZO nano-triangle arrays indicated that the absorption peaks of the PMMA overlapped with the SPR peaks of GZO nano-triangle arrays (on-resonance) could be enhanced. However, the off-resonance peaks of the PMMA could not be enhanced. [ABSTRACT FROM AUTHOR]

Abstract: The nonlinear absorption (NLA) properties of copper phthalocyanine (CuPc) solution in acetone were investigated by the femtosecond open-aperture (OA) Z-scan technique. The reverse saturable absorption (RSA) phenomenon was observed. And the physical mechanism of RSA effect was revealed, which was originated from three-photon absorption. Moreover, the influences of concentration and excitation laser power on the NLA of CuPc solution were studied respectively. Results showed that the RSA effect increased with the increase of sample concentration and excitation laser power. It indicated that the CuPc could be a promising candidate for optical limiting material. [Copyright &y& Elsevier]

Abstract: CuO nanocrystalline thin films are deposited on quartz substrates by pulsed laser deposition. The grown single-phase CuO films are characterized by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy. The optical nonlinearity of CuO films is investigated by the Z-scan method under a high-repetition-rate (HRR) femtosecond laser (800nm, 50fs, 80MHz). The CuO nanocrystalline films are found to be good optical limiters with a limiting threshold of 0.3GW/cm2 and a damage threshold of 1.65GW/cm2. The possible mechanisms of the optical limiting are also proposed. [Copyright &y& Elsevier]

Abstract: Phthalocyanines are promising molecules which present very attractive properties for nonlinear optical applications. The optical limiting performances of copper phthalocyanine and polychloro copper phthalocyanine have been investigated using 1064-nm continuous wave laser. The output–input power characteristics and nonlinear transmission properties for different solutions of copper phthalocyanine and polychloro copper phthalocyanine in acetone at increasing concentration were obtained. The observed nonlinearities were interpreted theoretically by rate-equation within a three-level model. The good optical limiting performance is attributed to a reverse saturable absorption (RSA) mechanism. It indicates that both copper phthalocyanine and polychloro copper phthalocyanine could be promising candidates for optical limiting materials. [Copyright &y& Elsevier]

Abstract: La(Zn0.5Ti0.5)O3 powders were synthesized by the Pechini process using citric acid as a complexing agent. The effect of the molar ratio of citric acid to total metal cations concentration (CA/M) and the pH of the starting solution on the crystallization behavior of La(Zn0.5Ti0.5)O3 was investigated. Homogeneously mixed gel was obtained and transferred into resin through charring. Single-phase and well-crystallized La(Zn0.5Ti0.5)O3 powders were obtained at 1000 °C for 2 h. DSC, TG and XRD were used to characterize the precursors and derived powders. [Copyright &y& Elsevier]

Abstract: Filamentation and supercontinuum generation in cobalt phthalocyanine chloroform solution by 800 nm 50-fs Ti: sapphire laser pulse is investigated for the first time to the best of our knowledge. It is found that filamentation is triggered by self-focusing and defocusing. The main mechanism of supercontinuum and conical emission generation is self-phase modulation (SPM) enhanced by self-steepening of the pulse and group velocity dispersion (GVD). This investigation of organic dye solutions by fs laser is a good complementarity to study the propagation of powerful ultrashort laser pulses in liquid media. [Copyright &y& Elsevier]