Experimental laser beam profiles often deviate somewhat from the ideal Gaussian shape of the axisymmetric TEM(00) laser mode. To take these deviations into account when calculating light scattering of an off-axis beam by a spherical particle, we use our phase-modeling method to approximate the beam-shape coefficients in the partial wave expansion of an experimental laser beam. We then use these...

Abstract The main defect of additive manufacturing technology based on laser melting is that large thermal deformation easily generated inside the part during forming process. traditional method to adjust process parameters, stress relief annealing and other hardware methods. From point view design, this paper proposed a reduce by changing product structure configuration without form design goa...

We demonstrate that a laser beam converging from a specific transverse mode is a bottle beam, as described in J. Opt. Soc. Am. B 20, 1220 (2003). To our knowledge, this is the first time that a bottle beam has been generated directly from a laser. By calculating the radiation forces on a dielectric Rayleigh sphere in the bottle beam, we show that the single beam can trap high-refractive-index p...

The formation of a uniform, high tensile stress and low silicide/Si interfacial resistance nickel silicide in nMOSFET by introducing pulsed laser annealing (PLA) is reported. This annealing approach facilitated the phase transformation of nickel silicide to Si-rich NiSix compounds using a low-thermal-budget process, improves the silicide/Si interface regularity and avoids familiar (111) NiSi2 f...

treatment with antimicrobial chemotherapeutic agents, alternative approaches such as lethal photosensitization are being used. the aim of this study was to evaluate the effect of visible light and laser beam radiation in conjugation with three different photosensitizers on the survival of two main periodontopathogenic bacteria including porphyromonas gingivalis and fusobacterium nucleatum in di...

The rapid melting of silicon film due to the absorption of a CW laser beam radiation is studied. The silicon film melting and recrystallization is mainly controlled by the temperature distribution in the semiconductor. The enthalpy technique for the solution of phase change problems is used in an explicit finite difference form to calculate the transient temperature distribution in the silicon ...

OBJECTIVE To determine the efficacy of various eye protection measures during carbon dioxide laser laryngoscopy. DESIGN A standard medical mannequin was equipped with indicator paper over the eyes and subjected to multiple passes of direct carbon dioxide laser beam contact at 400-mm focal length with powers ranging from 2.5 to 4.0 W during simulated laser microlaryngoscopy. Several different ...

We report the characterization of aluminum oxide (Al2O3) films which are grown on Si substrates by electron beam evaporator. This paper focuses on the characteristic variation of Al2O3 films depending on the different annealing techniques, such as post-deposition annealing and post-metallization annealing. The capacitance-voltage (C-V) curves indicate a negative charge and interface trap charge...

In recent years, a number of laser based H beam diagnostics systems have been developed in the Spallation Neutron Source (SNS). This talk reviews three types of laser based diagnostics at SNS: the laser wire profile monitors at superconducting linac (SCL), the laser transverse emittance scanner at high energy beam transport (HEBT), and the laser bunch shape monitor at medium energy beam transpo...

In the present study, an ultrafine grained (UFG) 304L stainless steel with the average grain size of 300 nm was produced by a combination of cold rolling and annealing. Weldability of the UFG sample was studied by Nd: YAG laser welding under different welding conditions. Taguchi experimental design was used to optimize the effect of frequency, welding time, laser current and laser pulse duratio...