JLA Vol:22 Iss:4 (A fast method for morphological analysis of laser drilling holes)

Authors:
M. Schneider
L. Berthe
M. Muller
R. Fabbro
Laboratoire PIMM (CNRS) ARTS et METIERS ParisTech, 151 Boulevard de l’Hopital, 75013 Paris, France

This paper presents an original method for analyzing laser drilled holes. The so-called Direct Observation of Drilled hOle (DODO) method is introduced and its applications. The hole characterization that’s been made is compared with x-ray radiography and cross-section analysis. Direct Observation of Drilled hole provides instantaneously surface state, geometric shape, as well as recast layer structure, without additional operation. Since no mounting resin is used to embed the sample, th...

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:25 Iss:5 (Investigation into the effects of process parameters on bending angle in the laser bending of tailor machined blanks based on a statistical analysis)

Authors:
Mehdi Safari
Mahmoud Farzin
Abbas Ghaei
Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran

In this paper, the effects of process parameters on bending angle in laser bending of tailor machined blanks are investigated experimentally. The Taguchi experimental design method is employed to study various parameters, which significantly affect the bending angle in the laser bending of tailor machined blanks. The start point of scan path, irradiating method, laser output power, beam diameter, and number of radiation passes are considered in the evaluations. A L₁₈(2¹×3⁴) Ta...

JLA Vol:17 Iss:2 (Feedback control effects on dimensions and defects of H13 tool steel by direct metal deposition process)

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

As a promising and novel manufacturing technology, laser aided direct metal deposition (DMD) process produces near-net-shape functional metal parts directly from the computer aided design (CAD) model. In-process feedback control has been recognized as a critical element to ensure the dimensional accuracy as well as near-net-shape production. Furthermore, process parameters should be delicately controlled to produce defect-free parts with superior mechanical properties. A closed loop real-time optical height control system...

JLA Vol:21 Iss:4 (Numerical model of a laser-sustained argon plasma)

Authors:
R. Akarapu
A. R. Nassar
Department of Engineering Science and Mechanics, Penn State University, University Park, Pennsylvania 16802-6812

S. M. Copley
Applied Research Laboratory and Department of Mechanical and Nuclear Engineering, Penn State University, University Park, Pennsylvania 16802-6812

J. A. Todd
Department of Engineering Science and Mechanics, Penn State University, University Park, Pennsylvania 16802-6812

A steady state axi-symmetric model was developed to predict the size, shape and temperature of a laser-sustained plasma in flowing argon. The power of the carbon dioxide (CO₂) laser and the free s...

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:1 Iss:4 (Laser Accidents: Are They All Reported and What Can Be Learned from Them?)

Authors:
R. James Rockwell
Rockwell Laser Industries, Cincinnati, Ohio

JLA Vol:15 Iss:3 (Preparation of polyperinaphthalenic organic semiconductive nanoparticles by excimer laser ablation and their application to optic and electronic devices)

Authors:
Satoru Nishio
Hiroshi Fukumura
Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Sendai, Miyagi 980-8578, Japan

Kazuyuki Tamura
Jun Murata
Junko Kitahara
Teruhiko Kan
Akiyoshi Matsuzaki
Department of Chemistry for Materials, Faculty of Engineering, Mi’e University, 1515 Kamihama-cho, Tsu, Mi’e 514-8507, Japan

Nobuo Ando
Yukinori Hato
Kanebo LTD., 3-1, Kanebo-cho, Hofu, Yamaguchi 747-0823, Japan

Polyperinaphthalene (PPN) nanoparticles are prepared by excimer laser ablation (ELA) of a 3, 4, 9, 10-perylenetetracarbox...

JLA Vol:19 Iss:4 (Bench-top antigen detection technique that utilizes nanofiltration and fluorescent dyes which emit and absorb light in the near infrared)

Authors:
Vanessa A. Varaljay-Spence
Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, Ohio 44115, NASA Glenn Research Center at Lewis Field, Brook Park, Ohio 44135, and Department of Microbiology, University of Georgia, Athens, Georgia 30602

Maximilian C. Scardelletti
NASA Glenn Research Center at Lewis Field, Brook Park, Ohio 44135

This article discusses the development of a bench-top technique to detect antigens in fluids. The technique involves the use of near infrared (NIR) fluorescent dyes conjugated to antibodies, centrifugation, nanofilters, and spectrometry. The system used to detect the antigens utili...