JLA Vol:7 Iss:1 (Taking advantage of laser properties to enhance demonstrations and student laboratories)

Authors:
Michele L. Brill
Camden County College—Physics/Lasers, Box 200, Blackwood, NJ 08012, U.S.A.

This paper reflects the proceedings of a workshop for local educators provided by Camden County College Laser Curriculum faculty which addressed the question: ‘How can the teacher take advantage of laser properties to improve or enhance demonstrations and student labs?’ Explored here are illustrative ways in which to utilize, for educational purposes, the three well‐known characteristics of lasers: monochromaticity, directionality, and coherence. There is a faculty overlap between the Physics Department and the Laser Curriculum faculty at the college. The use o...

JLA Vol:14 Iss:1 (Experimental study on surface decontamination by laser ablation)

Authors:
X. Zhou
K. Imasaki
H. Furukawa
C. Yamanaka
Institute for Laser Technology, 2-6 Yamada-oka, Suita, Osaka 565-0871, Japan

S. Nakai
Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871, Japan

A high-power pulsed Nd:YAG laser was employed to irradiate a 20-μm-thick Zn coating on a carbon steel surface. The ablation rate was defined as ablated volume divided by consumed laser energy, and was used to assess ablation cleaning ability. The relationships of ablation rate to laser pulse width and ablation rate to laser fluence were investigated, and optimal processing conditions were dete...

JLA Vol:18 Iss:1 (Optical viewport assembly for eye-safe monitoring of thin film deposition)

Authors:
Kevin Robbie
Cristina Buzea
Olivier Landry
Cory Dean
Department of Physics, Queen’s University, Kingston, Ontario K7L 3N6, Canada

This article discusses the design and application of a simple eye-safe monitoring assembly of thin film deposition and its advantages over the existent eye protection filters. This assembly prevents users from being exposed to the radiation field caused by lasers or incandescent objects during thin film deposition. Its design is simple, the device being reliable and easy to operate.

JLA Vol:9 Iss:3 (A power distribution model of industrial CO₂ lasers for system diagnosis)

Authors:
James G. Katter
Jay F. Tu
Mark Gartner

Industrial lasers are high power pieces of equipment that occasionally function under undesirable operating conditions. For example, the performance of a transverse‐flow d.c.‐excited gas laser can be adversely affected by many factors such as electrode arcing, poor lens and mirror cleanliness, focusing problems, improper gas mixture composition, poor gas quality, poor beam stability, poor beam path cleanliness, operator error, poor maintenance, poor chiller water temperature and flow rate stability, and improper laser beam ramp‐in/ramp‐out rates. Many of these factors which occur in ...

JLA Vol:4 Iss:1 (Laser Triangulation Range Sensors: A Study of Performance Limitations)

Authors:
Michael Buzinski
Alan Levine
Warren H. Stevenson
Applied Optics Laboratory, School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907

Optical triangulation is a very old method of determining absolute distance to an object. In recent years laser range sensors utilizing this principle have seen growing use, particularly in the auto industry. More accurate versions are being employed for dimensional inspection operations where the sensor is often mounted on a coordinate measuring machine. Such a system offers the potential for rapid non‐contact dimensional metrology. However, there are several factors which must be taken int...

JLA Vol:25 Iss:4 (On the exposure limits for extended source multiple pulse laser exposures)

JLA Vol:23 Iss:2 (Microcomputed tomography analysis of intralayer porosity generation in laser direct metal deposition and its causes)

Authors:
M. Naveed Ahsan
Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Sackville Street, Manchester M13 9PL, United Kingdom

Robert Bradley
Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester, Grosvenor Street, Manchester M13 9PL, United Kingdom

Andrew J. Pinkerton
Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Sackville Street, Manchester M13 9PL, United Kingdom

Laser direct metal deposition has wide application in the areas of rapid manufacturing, surface coating, and compon...

JLA Vol:7 Iss:4 (Laser applications in science education (LASE) Project: an introduction to photonics at the secondary school level)

Authors:
Gareth T. Williams
Physics Department, San Jose State University, San Jose, California, U.S.A.

JLA Vol:14 Iss:3 (Appropriate regimes of laser drilling models containing melt eject mechanisms)

Authors:
S. S. Kudesia
Department of Physics, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, United Kingdom

P. Solana
Departamento de Matema´tica Aplicada, Universidad Polite´cnica de Madrid, Spain

W. S. O. Rodden
D. P. Hand
J. D. C. Jones
Department of Physics, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, United Kingdom

The significance of melt ejection during various drilling regimes of laser drilling is investigated. The predictions of two analytical models of the drilling process, with and without the melt ejection mechanism, are compared with experimental measurements made using a ...

JLA Vol:18 Iss:3 (Multiscale modeling of solidification during laser cladding process)

Authors:
Y. Cao
J. Choi
Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, Rolla, Missouri 65409-1060

Laser cladding is an additive manufacturing process in which a laser generates a melt pool on the substrate material while a second material in a powder or wire form is injected into that melt pool. Among all laser manufacturing processes, laser cladding offers the most extensive variety of possibilities to alter a component at its surface. Despite immense potential and advancements, the process model of microstructure evolution and its coupling with macro parameters of the laser cladding process has not been fully developed. To address this...