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Showing 1 to 20 of 231 for “"laser beam"”.
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High current coaxial ion beam/laser beam spectrometer
… of molecular ions is described. In the new ion beam machine, the ion beam and laser beam overlap in a coaxial geometry. The machine has much higher ion current than an apparatus previous used. The laser beam induces transitions between internal states of the molecular ion. The transitions are …
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Laser beam induced current studies of Hg1-xCdxTe photodiodes
Laser-beam-induced-current (LBIC) is being investigated as a combined electro-optical (EO) alternative to individual electrical and optical based measurements of p-n junction photodiodes. The technique is non-destructive and employs a focused low-power laser beam that is scanned across the …
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High Accuracy Mobile 3D Scanning Using Structured Laser Beam Patterning
… System (DDRS), which consists of a smartphone, a laser projector, and the main algorithm, which extracts the data from the DDRS for volume and nutritional calculations. The DDRS software consists of four main algorithms: Automatic Laser Detection algorithm, Segmentation algorithm, 3D Mapping …
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Theoretical Study of Laser Beam Quality and Pulse Shaping by Volume Bragg Gratings
… also study theoretically various definitions of laser beam width in a given cross-section. Quality of the beam is characterized by the dimensionless beam propagation products (?x???_x)?? , which are different for each of the 21 definitions. We study six particular beams and introduce an …
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Microstructure and properties of laser beam and gas tungsten arc welded zirconium-2.5niobium
… processes in reactor core fabrication, namely laser beam welding (LBW) and gas tungsten arc welding (GTAW), were applied. Dilatometry was performed on cooling from 1050°C at varying cooling rates ranging between 0.5-600°C/s. In addition, tensile and micro-Vickers hardness tests were done to …
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A Novel Process to Create Arbitrary Microcellular Patterns in Polycarbonate using a Laser Beam
… nucleate microcells in polycarbonate sheets via laser beam. This method allows local heating of CO2 saturated polycarbonates which results in the creation of arbitrary shapes of microcellular foamed regions in a plastic part. We present the processing parameters required to create foams in …
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Predicting the Spatial Output Field of a Laser Beam in a Thermally Self-Induced Inhomogeneous Medium
Laser beam propagation in a thermally self-induced inhomogeneous medium is investigated to find the transient spatial output field for an arbitrary incident field. The paraxial wave equation is coupled with the heat diffusion equation to predict the beam output field as the index of refraction …
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Coherent and partially coherent CW laser beam propagation in lens-like media: a diffractive ray-theoretic approach
… effects associated with the propagation of beamed signals, is illustrated in this thesis by considering the propagation of coherent and partially coherent cw Gaussian laser beams in lens-like media (e.g., selfoc fibers, laser induced plasmas, etc.). The main results presented here extend …
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A Feasiblity Study on the Fatigue Performance of Laser Beam Welds and Hybrid-Laser Arc Welds Used in an Innovative Modular Steel Sandwich Panel Bridge Deck SyStem
… explores the feasibility of implementing a laser welded sandwich steel panel bridge deck system as a viable alternative to standardized reinforced concrete bridge decks. Generally used in naval ship building applications, steel sandwich panels possess attractive characteristics towards the …
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Influence of Induced natural convection on laser propagation : analysis and interferometric visualization
… flow on the propagation of a high energy laser beam. The two configurations considered are of a vertical laser beam (propagation direction opposite to gravity) and a horizontal laser beam (gravity acting in a direction perpendicular to propagation) traveling through an infinite expanse of …
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Effect of electric fields on the synthesis of nanoparticles of tin and silicon in a liquid environment
… and morphology of nanoparticles fabricated by laser ablation was investigated. In this method, a pulsed laser beam was focused onto a solid target of either silicon or tin and the laser beam ablated the target at the liquid-solid interface. The laser beam vaporizes the target material forming a …
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Smart photonics in imaging and sensing
… First, the design of an embedded systems based laser beam imager and spectrum analyser deploying a Digital Micromirror Device is described and demonstrated. The performance of the proposed laser beam imager is experimentally compared versus a commercial industrially deployed profiler, for a …
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Novel smart modules for imaging, communications, and displays
… (DMD). The proposed modules include imagers for laser characterization and general purpose imaging which smartly adapt to changes in irradiance, optical wireless communication systems which can adapt to the number of users and to changes in link length, and a smart laser projection display that …
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The refractive effects of laser propagation through the ocean and within the ocean
… the effect of the ocean water attenuation on a laser beam fired upward inside the ocean. The laser beam spreading due to scattering is approximated. The method used is a computer Monte Carlo simulation. Angular spreading of light caused by refraction at the sea surface is also studied and …
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Optical Detection of Ultracold Neutral Calcium Plasmas
… plasma. We probe the plasma with a 397 nm laser beam tuned to a calcium ion transition. The probe laser beam is focused to a 160 µm waist allowing fine spatial resolution. Ions are detected by measuring fluorescence using a Photo-Multiplier Tube (PMT). The signal, an average of 4000 …
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