JLA Vol:4 Iss:3 (Technical Training Approach — Safe operations, maintenance and service of lasers in manufacturing)

Authors:
Phillip Hoffman
General Motors Corporation

JLA Vol:4 Iss:2 (Application of an Excimer Laser Machining Technique in the Construction of an Optical Fiber Bus)

Authors:
Richard J. Coyle
A. J. Serafino
AT&T Bell Laboratories, P.O. Box 900, Princeton, New Jersey 08540

Gary J. Grimes
James R. Bortolini
AT&T Bell Laboratories, 11900 North Pecos Street, Denver, Colorado 80234

An excimer laser technique was developed to machine precision tap openings in a polymer‐clad silica optical fiber for use in the construction of an optical backplane. In this technique, a telescope was used to image the laser beam onto the surface of the fiber at the desired tap location. The cladding then was removed using a prescribed number of pulses from the excimer laser. Single optical fiber taps were cons...

JLA Vol:4 Iss:2 (A Systematic Method for the Design of a Multivariable Controller Actuating Power and Speed during a CO₂ Laser Surface Treatment)

Authors:
F. Bataille
J. M. Cerez
D. Kechemair

Temperature control systems actuating laser power and scanning velocity during laser surface hardening have already been presented. This paper exposes a systematic method for the design of a multivariable Linear Quadratic Gaussian controller adapted to this laser treatment. The preliminary identification step and the controller design are included. This corrector insures a better regulation and the generality of the method hopefully allows an easier adaptation to other laser treatments, materials or absorbing coatings.

JLA Vol:4 Iss:2 (Dynamic Laser Doppler Velocimetry on Solid Surfaces)

Authors:
Milind M. Rajadhyaksha
Warren H. Stevenson
Applied Optics Laboratory, School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, U.S.A.

This paper presents the results of a detailed analytical and experimental investigation into the accuracy of a differential laser Doppler velocimeter (LDV) for dynamic, solid surface velocity measurements made over very short averaging times on the order of one millisecond. Accuracy limitations are derived, along with operating conditions and signal processing considerations needed to optimize LDV performance. An experiment is described which demonstrates the use of an LDV to instantaneously and accurate...

JLA Vol:4 Iss:2 (Fracture Characteristics of an Aluminum Oxide Ceramic during Continuous Wave Carbon Dioxide Laser Cutting)

Authors:
R. N. Smith
R. P. Surprenant
D. A. Kaminski
Department of Mechanical Engineering, Aeronautical Engineering and Mechanics, Rensselaer Polytechnic Institute, Troy, New York 12180‐3590

A series of experiments was conducted to determine the influence of workpiece thickness, cutting speed, and beam power on the onset of fracture in aluminum oxide (Al₂O₃) during continuous wave CO₂ laser cutting. Samples of Coors AD‐96 substrate of thickness 0.040, 0.050, and 0.080 in. thick, respectively, were cut at combinations of feedrates and power levels to determine the conditions at which fracture of this ceramic occu...

JLA Vol:4 Iss:2 (On‐The‐Fly Drilling with a Fiber Delivered Face Pumped Laser Beam)

Authors:
Angel L. Ortiz
General Electric Corporate Research and Development, 1 River Road, P.O. Box 8, Bldg. KWC‐617, Schenectady, New York 12301

A high power Neodymium: Yttrium‐Aluminum‐Garnet (Nd:YAG) Total‐lnternal‐Reflection Face Pumped Laser (TIR‐FPL) coupled with a fiber delivery system has been proven to be a powerful processing tool for On‐The‐Fly (OTF) drilling [1–3]. Single‐Pulse OTF drilling, (i.e., one laser pulse per hole with continuous part motion) at shallow angles to the surface with material thicknesses up to 50 mils can be easily accomplished generating good quality holes. Optical sensors...

JLA Vol:4 Iss:3 (Engineered Safety: First Line of Defense)

Authors:
Melvin D. Barger

JLA Vol:4 Iss:3 (Probing Plume Protection Problems in the Health Care Environment)

Authors:
John M. Kokosa
Marcus D. Benedetto
GMI Engineering & Management Institute, Flint, MI 48504, Ophthalmic Research, P.O. Box 560933, Orlando, FL 32856

This paper presents pragmatic particulars pertaining to plume protection problems with special emphasis on the health care environment. Practical approaches to optimizing protection are discussed with an eye toward facilitating the safety of personnel and the general health care environment from particulates, parasites, viruses and other undesirable entities, elements and compounds.

JLA Vol:4 Iss:3 (In the Canadian World: No Second Chances)

Authors:
Jeff Elie

JLA Vol:4 Iss:1 (TEA CO₂ Laser&hyphen;Induced Infrared Multiphoton Dissociation of Zirconium Tetra&hyphen;<em>tert</em>&hyphen;Butoxide: Reaction Mechanism and Dissociation Products)

Authors:
Yoshiki Okada
Shuji Kato
Sakae Satooka
Kazuo Takeuchi
The Institute of Physical and Chemical Research, Wako, Saitama 351&hyphen;01, Japan

Experiments of laser irradiation were performed to investigate the reaction mechanism of TEA CO₂ laser&hyphen;induced dissociation of zirconium tetra&hyphen;tert&hyphen;butoxide (Zr(t&hyphen;OC₄H₉)₄). The chemical structure of the dissociation product was analyzd by fast atom bombardment mass spectrometry (FAB&hyphen;MS), infrared absorption spectroscopy, Raman spectroscopy, and ¹H and ¹³C nuclear magnetic resonance (N...