Harold D. Wallace Jr., Associate Curator, Nat'l Museum of American History
|Ebe Helm operating his laser in his high school lab, 1979. Courtesy of Ebe Helm.|
Even after half a century the word "laser" conjures up images of laboratories and high-tech complexity. In the National Museum of American History anniversary showcase, "Lasers: The First 50Years," I wanted to show the speed with which both professional and amateur inventors embraced the device. So along with seminal inventions--a ruby laser from Theodore Maiman, laser crystals from Peter Sorokin, and Ali Javan's helium-neon laser--we display a range of objects that illustrate some of the many applications to which lasers have been adapted.
One of my favorite pieces is the gas laser assembled by teenager Ebe Helm in the basement of his parents' New Jersey home in 1979. Combining an interest in science with strong mechanical aptitude, Helm first became interested in lasers by repairing a ruby laser used in an exhibition at the Franklin Institute. As he learned more about lasers he corresponded with engineers in various corporate and academic laboratories, whom Helm recalled being "very supportive and enthusiastic."
Working from plans published by Information Unlimited, Helm began designing a carbon-dioxide (CO2) gas laser. In correspondence leading up to his donation of objects to the Museum in 2005, he described the project:
"The tube was hand made for me by Arthur H. Thomas Co. of Philadelphia, and [an engineer from] Standard-Thomson Corporation provided the brass bellows. The brass and copper to make the mirror mounts were given to me by South Jersey Welding Supply and cut to my requested specs by the machine shop at Siemens [in] Cherry Hill, N.J. The zinc selenide output mirror [and the vacuum gauge and valves were] donated by the Valtec Corporation of Holliston, Mass. This allowed me to use a helium neon laser for alignment [of the optics on my laser].
|Ebe Helm built this carbon-dioxide laser in his parents' basement. Photo by Harold Dorwin, Smithsonian Institution.|
"The target is a building block donated from the nursery school that my mother operated from our home. From my earlier work on the ruby laser, I learned to use a layered target. Plastic food wrap over carbon paper over wood, in this case, gave a graduated indication of power output."
Helm also remembered having to reassure his mother, as he worked in his basement lab, that the very loud noise created by a nearby train derailment was none of his doing.
But not all of his laser work happened in his basement. "I often liked to muse at the fact," he told us, "that I was given my own science classroom to use as a lab, not because I was anything special, but because my teachers knew this stuff was dangerous. High voltage, high vacuum, high pressure gas, and let's throw in laser radiation just for good measure. I was in my glory. I think I had them all a little scared. It was fun."
Both Helm's CO2 laser and the target block that shows the scars of use are currently on display. His donation also includes the ruby laser and nearly a dozen other early commercial lasers with which he experimented.
From Prototype, March 2010