JLA Vol:3 Iss:3 (Safety of Medical Excimer Lasers with an Emphasis on Compressed Gases)

Authors:
David H. Sliney
Laser Microwave Division, US Army Environmental Hygiene Agency, Aberdeen Proving Ground, MD 21010‐5422

Terrance N. Clapham
VISX, Inc., 919 Kifer Road, Santa Clara, CA 94086

Excimer lasers which emit short ultraviolet radiation (UVR) are currently being used in experimental and developmental surgical applications. Although UVR exposure is possible, it is not normal in laser angioplasty (cardiovascular surgery) and is insignificant in photokera‐toplasty (ophthalmic surgery). However, significant potential hazards exist with the use of excimer laser gases such as fluorine and HCI. Stringent safeguards for handling and use are ...

JLA Vol:16 Iss:4 (Microstructural aspects of laser dissimilar welds of hard metals to steels)

Authors:
A. Costa
IDMEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal

L. Quintino
IDMEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal and Instituto Superior Te´cnico, Secc¸a˜o de Tecnologia Mecaˆnica, Av. Rovisco Pais, 1049-001 Lisboa, Portugal

R. M. Miranda
IDMEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal and Universidade Aberta, R. Escola Polite´cnica 147, 1269-001 Lisboa, Portugal

Laser beam welding has been widely used in industry in the past decade. Recently, applications in dissimilar welds involving hard metals have been investigated. Hard metals are commonly used in tool manufacturing and this application...

JLA Vol:21 Iss:1 (Local susceptibility of the retina, formation and duration of afterimages in the case of Class 1 laser products, and disability glare arising from high-brightness light emitting diodes)

Authors:
Hans-Dieter Reidenbach
Cologne University of Applied Sciences, Research Laboratory on Medical Technology and Non-Ionizing Radiation, Betzdorfer Str 2, 50679 Koeln, Germany

According to the new European Directive on Artificial Optical Radiation, the employer has to determine the exposure and the assessment of risks and in addition, he shall give particular attention to any indirect effects, such as temporary blinding, when carrying out the risk assessment. Up to now, secondary effects such as temporary blinding have not been regarded in safety standards and there exist but a few data on this topic as far as modern artificial high-brightness (HB) light sources are concerned. Te...

JLA Vol:1 Iss:2 (Summary of Laser Plume Effects and Safety Session)

Authors:
Richard P. Felten
Senior Chemist, Radiation Biology Branch, Center for Devices and Radiological Health, Food and Drug Administration

JLA Vol:24 Iss:2 (Laser dressing of metal bonded diamond blades for cutting of hard brittle materials)

Authors:
Philipp von Witzendorff
Anas Moalem
Rainer Kling
Ludger Overmeyer
Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany

In this study, the authors investigate the laser dressing of metal bonded diamond blades by means of laser pulses with different pulse durations and wavelengths. Conventional dressing suffers from excessive blade wear, whereas laser dressing enables precise removal of the bonding metal to generate the required chip space of protruding diamond grains. The challenge for processing this composite material is to find appropriate level of ablation for the bonding metal without damaging the diamond grains thr...

JLA Vol:6 Iss:3 (Safety concerns about laser pointers)

Authors:
David H. Sliney
Jerome E. Dennis

In the past two years considerable concerns have been expressed about the safety of Class 3A laser pointers. The concern has been that Class 3A diode–laser pointers have replaced the safer helium–neon (He–Ne) Class 2 laser pointers. Hundreds of thousands of small He–Ne visible‐wavelength lasers have been traditionally used for alignment and pointing, laser demonstrations and laser displays in science, education and industry, but can the diode laser be as safe and effective? Not infrequently, some people associate “lasers” with Buck Rogers and “Star Wars”, and are concerned wh...

JLA Vol:15 Iss:1 (Microstructure and corrosion behavior of high power diode laser deposited Inconel 625 coatings)

Authors:
J. Tuominen
Laser Application Laboratory, Tampere University of Technology, FIN-33101 Tampere, Finland

P. Vuoristo
T. Ma¨ntyla¨
Institute of Materials Science, Tampere University of Technology, FIN-33101 Tampere, Finland

J. Latokartano
J. Vihinen
Laser Application Laboratory, Tampere University of Technology, FIN-33101 Tampere, Finland

P. H. Andersson
Institute of Production Engineering, Tampere University of Technology, FIN-33101 Tampere, Finland

A series of experiments were performed to investigate the one-step laser cladding of Inconel 625 powder, injected off-axially onto m...

JLA Vol:19 Iss:2 (Welding of titanium and other refractory metals with a free pulse shaping laser)

Authors:
Karsten Richter
Lasag AG, Switzerland

Uwe Reisgen
Wilfried Behr
Forschungszentrum Ju¨lich GmbH, Germany

Ronald Holtz
Lasag AG, Switzerland

Refractory metals are used as construction materials for specific applications. Amongst the refractory metals, titanium has a special status due to its multi-faceted property profile and its comparatively low price. Titanium materials have outstanding properties, such as excellent resistance to corrosion and very high strength at low densities, which lead to their preferred use in chemical engineering and as a structural material in lightweight construction. Due to the high affin...

JLA Vol:8 Iss:5 (Laser drilling of advanced materials: Effects of peak power, pulse format, and wavelength)

Authors:
X. Chen
W. T. Lotshaw
A. L. Ortiz
P. R. Staver
C. E. Erikson
M. H. McLaughlin
T. J. Rockstroh

The quality of laser‐drilled holes is significantly influenced by the laser peak power, pulse format, and wavelength. Three advanced materials are used to demonstrate the importance of choosing the correct laser parameters for a specific material. The materials are: (1) intermetallic single crystal nickel aluminide (NiAl) alloy; (2) N5, a single crystal nickel‐based superalloy; and (3) a silicon carbide (SiC) ceramic matrix composite (CMC). The laser peak power is varied in terms of the pulse...

JLA Vol:2 Iss:1 (On Laser Vibrometry of Rotating Targets: Effects of Torsional and In‐Plane Vibration)

Authors:
S. J. Rothberg
J. R. Baker
N. A. Halliwell
ISVR, University of Southampton, Highfield, Southampton S09 5NH, England

Vibration measurements on rotating surfaces are often referred to in the commercial literature as a major application of laser Doppler vibration transducers. This paper examines such use of these instruments and shows how the presence of a velocity component due to the rotation itself leads to spurious measurement dependence on both torsional vibration and motion perpendicular to the line of incidence of the laser beam. In addition, the scale of this dependence increases with both rotation speed and perpendicular distance between the l...