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:1 (ANSI Z136.1 Proposed 1992 Changes)

Authors:
R. James Rockwell
Wesley J. Marshall
Myron L. Wolbarsht
David H. Sliney

JLA Vol:3 Iss:3 (Determining Weld Quality in Pulsed Nd:YAG Laser Spot Welds)

Authors:
H. N. Bransch
Z. Y. Wang
J. T. Liu
D. C. Weckman
H. W. Kerr
Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1

For pulsed Nd:YAG laser spot welding applications, the development of optimum welding procedures ought to include various measures of weld size and quality, such as weld diameter, depth, surface contour and porosity. A split‐specimen technique has been developed that, despite the small size of the welds, allows such measurements to be made faster and more accurately than the traditional metallurgical technique involving sectioning, polishing and etching. In the sp...

JLA Vol:3 Iss:3 (ANSI Z136.2 Update: Ocular Effects of Laser Infrared Radiation)

Authors:
William T. Ham
Harold A. Mueller
Division of Biome´dical Engineering, Department of Biostatistics, Virginia Commonwealth University, Richmond, Virginia

Laser radiation employed in fiber optic communications systems is a possible hazard to the eyes of personnel working with or maintaining such equipment. To investigate the potential hazard of infrared laser wavelengths centered around 1550 nm we exposed the corneas of 12 Dutch belted rabbits to a laser diode furnished by Bell Laboratories. Maximum power output through a 4‐meter fiber optic cable was 5.6 mW. Anesthetized and fully dilated rabbits were exposed for time durations of 1, 10 and 100 s to po...

JLA Vol:3 Iss:3 (Impact of International Laser Safety Standards on Manufacturers. Part II)

Authors:
Robert Weiner
Weiner Associates, Manhattan Beach, CA

Manufacturers have an increasing concern about the need to satisfy different laser safety regulations as they market their products throughout the world. While the national and regional laser safety regulations are similar, the differences which exist do impact the product. The requirements may vary in measurement criteria and limits for classification, engineering features, and manuals and labels, as well as for reporting, testing, and certification. This paper discusses the impact of the primary differing requirements on specific product types and describes the manner in which the laser safety standards are being implemented.

JLA Vol:4 Iss:1 (Combustion‐Assisted Laser Cutting of a Difficult‐to‐Machine Superalloy)

Authors:
P. A. Molian
M. Baldwin

In laser cutting, the largest single application of lasers in manufacturing, the assist gas plays an important role in affecting the cutting performance. The assist gas is usually oxygen or an inert gas. In this work a mixture of acetylene and oxygen was employed to create combustion reactions during CO₂ laser cutting that enabled an improvement in the cutting speed, and cut quality of a difficult‐to‐machine superalloy. A comparison with laser cutting of a plain carbon steel under identical conditions was also made to determine the usefulness of combustion energy. Results indicate that both cutting speed and qual...

JLA Vol:4 Iss:1 (The Impact of European Standards, Directives and the CE Mark)

Authors:
A. Roy Henderson
Bioptica, St. John's Innovation Park, Cambridge U.K.

JLA Vol:4 Iss:1 (Laser Safety in Health Care Facilities)

Authors:
Rocco V. Lobraico
Chairman, ANSI Z136.3 Committee

JLA Vol:4 Iss:1 (Laser Surfacing of High Density Polyethylene for Reduction in Fuel Permeability)

Authors:
W. W. Duley
M. Ogmen
T. Steel
S. Mihailov

The effect of UV and CO₂ laser radiation on the surface of HDPE gas tank material in relation to the permeability of this surface to unleaded gasoline has been investigated. It is found that while excimer (UV) laser radiation has no effect on permeability, CO₂ laser radiation at low intensity modifies the surface so as to reduce permeability over timescales of 1 – 2 days. A possible origin for this modification is suggested.

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...