• JLA Vol:18 Iss:2 (Investigation of the effects of nonconventional beam geometries in laser surface treatment of ceramics: Theoretical analysis)


    Authors:
    D. Triantafyllidis
    Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M60 1QD, United Kingdom and Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 IQD, United Kingdom

    L. Li
    Laser Processing Research Center, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M60 1QD, United Kingdom

    F. H. Stott
    Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD, United Kingdom


    Laser surface treatment of ceramics by melting and re...

    $25.00

  • JLA Vol:1 Iss:3 (Chemical Composition of Laser‐Tissue Interaction Smoke Plume)


    Authors:
    John M. Kokosa
    GMI Engineering & Management Institute, Flint, Michigan 48504 U.S.A.

    John Eugene
    Beckman Laser Institute, Irvine, California 92715 U.S.A.


    Lasers are assuming an increasingly important role in surgical procedures. However, several studies have shown that the smoke produced by laser‐tissue interaction is an airway irritant. Preliminary studies in our laboratories have shown that potentially hazardous chemicals, including benzene, formaldehyde and acrolein are present in the smoke plume resulting from CO2 and Nd:YAG laser interaction with animal tissue, even at low power densities. Since these chemicals are classified a...

    $25.00

  • JLA Vol:8 Iss:3 (Theoretical and experimental studies of thick‐section cutting with a chemical oxygen–iodine laser (COIL))


    Authors:
    A. Kar
    J. E. Scott
    W. P. Latham



    A simple mathematical model of thick‐section stainless steel cutting with a high power chemical oxygen–iodine laser (COIL) is presented and compared with experimental results obtained with a 10‐kilowatt COIL at the U.S. Air Force's Phillips Laboratory. This model uses a lumped‐parameter technique to relate the cutting kerf depth with various process parameters and can be used to predict scaled laser materials processing performance to very thick sections. The model is similar to an empirical model developed by researchers in Japan, but includes predictive capabilities for thick metal cutting...

    $25.00

  • JLA Vol:2 Iss:3 (Current State‐of‐the‐Art of Contouring Techniques in Manufacturing)


    Authors:
    Kevin G. Harding
    Industrial Technology Institute, Sensor Center for Improved Quality, Ann Arbor, Michigan 48106


    A manager with a major automobile manufacturer once made the comment that “the best thing we ever did to improve quality was give the guys on the floor a caliper to measure the parts”. As the tolerances on manufacturing become tighter, the need for accurate measurement has also increased. Hand fitting of parts to each other does not work in modern automated factories. Gauges in the past have been built to provide a fixed set of measurements of a known part. This practice too has been changing due to the trend toward flexible manufacturing. Now the gages...

    $25.00

  • JLA Vol:16 Iss:2 (Investigation of weld cracking in Nd:yttrium–aluminum–garnet keyhole spot welding of materials used in optoelectronic packaging)


    Authors:
    Geoff J. Shannon
    Unitek Miyachi Corporation, 1820 S. Myrtle Avenue, Monrovia, California 91017

    Bernard Q. Li
    Honeywell VCSEL Optical Division, Minnesota


    The welding of a problematic optical device weld joint between dissimilar materials is investigated in depth. The original material combination of cold rolled steel 1010 with 6 μm of gold coating and 304 L produced consistent weld cracking. The CRS1010 material was fixed, however the other component was open to material selection. The materials tested were 304 L stainless steel, kovar, invar, and Carpenter high permeability 49 alloy. The effect of these different materials, laser pulse parameters, lev...

    $25.00

  • JLA Vol:20 Iss:4 (Thermal stress analysis on laser scribing of glass)


    Authors:
    Koji Yamamoto
    Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan

    Noboru Hasaka
    Hideki Morita
    Mitsuboshi Diamond Industrial Co., Ltd., 2-12-12 Minami-Kaneden, Suita, Osaka, Japan

    Etsuji Ohmura
    Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan


    In the laser scribing of glass a thermal stress is introduced into a glass substrate by means of a CO2 laser irradiation. The glass substrate is then rapidly cooled down by water jet immediately after the irradiation. For the purpose of theoretical clarification of the factors ruling the scribable condit...

    $25.00

  • JLA Vol:24 Iss:4 (Morphology of nanoscale structures on fused silica surfaces from interaction with temporally tailored femtosecond pulses)


    Authors:
    Lars Englert
    Matthias Wollenhaupt
    Cristian Sarpe
    Dirk Otto
    Thomas Baumert
    Institut fuer Physik and CINSaT, Universitaet Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany


    Laser control of two basic ionization processes on fused silica, i.e., multiphoton ionization and avalanche ionization, with temporally asymmetric pulse envelopes is investigated. Control leads to different final electron densities/energies as the direct temporal intensity profile and the time inverted intensity profile address the two ionization processes in a different fashion. This results in observed different thresholds for material modification o...

    $25.00

  • JLA Vol:5 Iss:2 (Experimental Method for Determining the Coherence Length of CW Lasers Using a Michelson Interferometer)


    Authors:
    Sami Alaruri
    Allison Gas Turbine Division, General Motors Corporation, Sensor Development Group


    Theoretical analysis of the relationship between coherence length and the resonant‐longitudinal modes in an optical cavity is given. A Michelson interferometer is used to measure the coherence lengths of two CW He‐Ne laser cavities. Analysis of the experimental measurements shows good agreement with the theoretically predicted values.

    $25.00

  • JLA Vol:14 Iss:4 (High-energy femtosecond pulsed laser micromachining of thin film deposited silicon in self-focused air medium)


    Authors:
    Yuanyuan Dong
    Pal Molian
    Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011

    Christian Zorman
    Mehran Mehregany
    Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio 44106


    The ultrashort pulsed laser ablation of silicon wafers deposited with 1 μm thin film of SiC was performed in air medium using a 1 mJ, 120 fs, 800 nm Ti:sapphire laser, the objective being to determine the self-focusing capability of air to produce nanostructures. The effects of pulse energy, the number of pulses, pulse repetition rate and x–y translation speed on t...

    $25.00

  • JLA Vol:18 Iss:4 (Threshold powers and delays for igniting propane and butane-air mixtures by cw laser-heated small particles)


    Authors:
    Thomas H. Dubaniewicz
    National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, 626 Cochrans Mill Road, Pittsburgh, Pennsylvania 15236


    The National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory conducted a study of laser safety in potentially flammable environments. Researchers measured threshold igniting powers as a function of beam diameter for butane and propane-air mixtures by laser-heating targets placed on optical fiber tips using a 1064 nm laser. The minimum igniting powers for propane-air and butane-air were about 250 and 300 mW, respectively. Threshold igniting powers for propane-air were approxima...

    $25.00

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