JLA Vol:1 Iss:4 (FDA Medical Incident Report Is Sobering Reminder of Laser Safety Education Needs)

Authors:

JLA Vol:1 Iss:4 (Optical Engineering — A New Form of Industrial Energy)

Authors:
W. M. Steen

A brief review OF the development of civilization on this planet leads to a fairly strong correlation between our ability to apply new forms of energy and the growth of our quality of life. With the comparatively recent invention of the laser, optical energy has become available in a form and at intensities which can be applied. This article examines some of the differences between optical energy and other forms of industrial energy with a view to suggesting where future growth may occur and why our grand‐children may bask in a higher quality of life due to our efforts to apply this new form of energy. Some of the principle differences noted are: the current laser ...

JLA Vol:1 Iss:3 (Experimental Laser Welding Thermal Cycles)

Authors:
E. A. Metzbower
U.S. Naval Research Laboratory, Code 6324, Washington DC 20375‐5000, U.S.A.

JLA Vol:1 Iss:3 (Laser Welding of Plastics in Low and High Gravity Environments)

Authors:
R. E. Mueller
W. W. Duley
CRESS and Laser Processing Laboratory, York University, Toronto, Ontario, Canada M3J 1P3

S. MacLean
M. Garneau
B. Tryggvason
Canadian Astronaut Office, National Research Council, Ottawa, Ontario, Canada K1A 0R6

W. F. J. Evans
Atmospheric Environment Service, 4905 Dufferin Street, Downsview, Ontario M3H 5T4

Initial results of a series of laser processing experiments performed under the micro‐gravity conditions supplied by NASA's KC‐135 aircraft are presented. Weld morphologies of polypropylene and polyethylene were obtained under both hyper‐ and hy...

JLA Vol:1 Iss:3 (CO₂ Laser Engraving System for Relief Plate to Print Corrugated Cardboard)

Authors:
K. Wakabayashi
N. Sugishima
NEC Corporation, Laser Equipment Div., 1120, Shimokuzawa, Sagamihara, JAPAN

A very compact and economical CO₂ laser engraving system to make relief plates for the purpose of printing corrugated cardboard has been developed. This system consists of a highly stable 500W CO₂ laser and a high speed, easy handling image processing sub‐system. In this paper several new developments are described. This image processing technique for CO₂ laser raster scanning and engraving has been newly developed. Every binary image is converted to the relief plate more easier than other reported engraving systems.

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:1 Iss:2 (New Materials: Non‐Equilibrium Synthesis by Laser)

Authors:
J. Mazumder
S. Sircar
C. Ribaudo
A. Kar
Laser‐Aided Materials Processing Laboratory, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana‐Champaign, 1206 West Green Street, Urbana, Illinois 61801, U.S.A.

Synthesis of nonequilibrium phases provides an opportunity to engineer new materials with novel properties. The technique of laser surface modification (LSM) provides a unique means of synthesizing novel non‐equilibrium materials by taking advantage of the inherent rapid heating and cooling rate of the process. LSM can be used to obtain specific surface properties significantly diffe...

JLA Vol:1 Iss:2 (A Study in Surface Alloying of Titanium Alloys)

Authors:
A. Bharti
R. Sivakumar
Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad‐500 258, India

D. B. Goel
Department of Metallurgical Engineering, University of Roorkee, Roorkee‐247 667, India

A 5 KW CW CO₂ laser has been used to alloy the surface of Ti6Al4V alloy with carbon. As a result the average microhardness was increased from 365 to 600 kg/mm.² Compositional inhomogeneity was observed on the alloyed surface, however the compositional inhomogeneity index reduced considerably by cross scanning with defocused laser beam. Surface roughness of the alloyed surface was also studied and the roughn...

JLA Vol:1 Iss:2 (Measurement of Concentration of DHE in Tissue)

Authors:
A. Edward Profio
T. F. Khoury
Department of Chemical and Nuclear Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106 U.S.A.

Stephen Lam
School of Medicine, University of British Columbia, Vancouver, B.C., Canada

The effective absorbed dose in photodynamic therapy is proportional to the concentration of the photosensitizer, as well as to the radiant energy fluence and concentration of oxygen. The concentration of dihematoporphyrin ether/ester (DHE) has been measured in tissue specimens by chemical extraction followed by spectrofluorimetry against a standard solution, and by an in vivo fluorometer probe calibrated ag...

JLA Vol:1 Iss:2 (High Performance Laser Triangulation Ranging)

Authors:
C. Murray Penney
GE Corporate Research and Development, Schenectady, New York 12301

Brad Thomas
Johnson Laboratories, 383 Hillen Road, Towson, Maryland 21204

Laser triangulation ranging can provide data rates to at least 10,000 points per second, with resolution on the order of one thousandth of an inch, while observing strongly uncooperative targets through hostile environments. Data rate has been increased to greater than 100,000 points per second for applications requiring high resolution 3‐D maps of extended uncooperative surfaces. One successful approach to these applications is described. Also, several optical and engineering characteristic...