led the efforts culminating in a draft standard by the end of 1998 which revised and updated American National Standards Institute ͑ANSI͒ Z136.1-1993. This is now the fifth revision since 1973. This draft standard considers several major changes to revise laser hazard evaluation methods and laser classification for large sources. For collimated laser diode systems additional factors needed to be considered in order to maintain a fair margin of safety between the maximum permissable exposure ͑MPE͒ and actual injury thresholds for circular sources-with and without optically aided viewing. New data on ultrashort laser pulses ͑subnanosecond͒ changed the MPEs that were based on ''constant power'' criteria at 1 ns, while demonstrating new effects adversely impacting laser safety eyewear. Signs and labels are now more in accord with the latest ANSI Z535 and International Electrotechnical Commission recommendations.
In the early 1960s concerns about eye safety were concentrated in a handful of research laboratories and the military. Memoranda and guidelines were circulated internally with their own set of priorities and recommended practices. Then, in 1968, the First International Laser Safety Conference (the brainchild of Dr Leon Goldman), was held in Cincinnati with one of its avowed purposes, the development of a consensus among the most prominent investigators as to what exposure criteria should be adopted. They saw the (laser) light. By 1969 it had become clear that, because of widespread differences in the many laser safety practices, a national consensus standard was needed. The American National Standards Institute (ANSI) was requested by the US Department of Labor to initiate that project, and the Z136 committee began its work under Chairman George Wilkening. And, I was his secretary. The secretariat was the Telephone Group. It gives me great pleasure to point out that three of the original subcommittee chairs, R. James Rockwell Jr, David H. Sliney, and Myron I. Wolbarsht, are still actively committed to the Z136 Committee and the International Laser Safety Conference '97. One last final note: George M. Wilkening died June 30, 1995. The Laser Institute of America, Secretariat to the Z136 Committee, has established a ‘Wilkening’ Award for Laser Safety which was awarded March 17, 1997, at the meeting of the ILSC'97 in Orlando FL, to Dr W. T. Ham. Wilkening's dedication to laser safety lives on in Z136, and indeed throughout the world. He will be remembered as a tall man (6′6″) whose legs over-hung the beds on his travels, whose airplane seats were never big enough, whose technical knowledge of industrial health and safety was surpassed by none, and who always took the time to educate and explain. A great leader, a mediator, and a friend! We were told by ANSI that the ANSI Z136.1 standard ‘for the Safe Use of Lasers’ was completed in record time — only three years to final draft and publication in 1973. Since those early hectic days, the ASC Z136 Committee has revised and updated Z136.1 in 1976, 1980, 1986, and 1993. These we will touch upon. Meanwhile, the ASC Z136 Committee has issued, updated and is working on five other ANSI Z136.X standards. These standards have served as models for state, federal and international laser safety documents throughout the world.
New devices using vacuum‐deposited metal films require a high‐speed, low‐cost method of vacuum deposition. The capability of the open‐ended multiple‐chamber deposition equipment has been investigated to determine its suitability for depositing tantalum nitride thin films. This was accomplished by examining the measurable electrical properties of the deposited film and by determining the stability of resistors made from these films. Tantalum films produced by the open‐ended deposition system were found comparable to those produced by many bell‐jar systems. It was possible to control the addition of nitrogen to the films, and tantalum nitride films of satisfactory stability were obtained. Because the open‐ended deposition method can produce large quantities of suitable thin films, it is expected that this will be an important process in the manufacture of future products.
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