AFOSR's Laser Contributions Highlighted
WASHINGTON, Aug. 25, 2010 — Under the umbrella of “LaserFest” the Air Force Office of Scientific Research (AFOSR) hosted a series of celebrations to highlight the many Air Force and Defense Department-sponsored advances laser technology has made over the 50 years since its inception.
As part of the celebration Howard Schlossberg, AFOSR program manager participated in a “DoD Live” bloggers roundtable to discuss the 50th anniversary of the first laser, the ruby laser, as well as AFOSR’s contributions to laser science and technology and development of laser applications.
As a graduate student in 1962, only two years after the laser was invented, Schlossberg began his career in the field and has seen the laser develop from a single concentrated beam of visible light from a ruby laser into many different tools useful in medicine, mass production, communications, defense and numerous other fields.
“For me, over 48 years of a professional career that's been the excitement of the whole field — the interplay between the advancement of laser technology and the advancement of things you can do with lasers,” Schlossberg said. “But so much of the fundamental work that's been done in the country has really been sponsored by the Air Force. And this fundamental, long-range research has had huge impact around the country.”
Schlossberg said the Air Force’s developments come both in terms of new lasers and new applications for lasers. As new applications are found, new lasers are invented, and vice versa, he explained.
“We fit early into the airborne laser program when we funded the invention and much of the research that went into the laser that's used on that,” he said. “It's a so-called COIL laser, a chemical oxygen iodine laser, which produces very high powers needed in that application. As we speak, we are funding other kinds of lasers which might replace that laser and might be more convenient, particularly solid-state lasers.”
Solid-state lasers, he said, require only electricity to operate. The COIL system needs difficult chemical reactants to fuel the lasers, and then exhaust them. “Everybody believes that the next generation of high- powered lasers, of weapons, if that ever comes about, will be solid state,” Schlossberg said.
Beyond creating Star Wars-inspired laser weaponry, there have been numerous other experiments and potential applications for lasers in the military. One such example, device that detects roadside bombs, pairs lasers with radar to try to create and detect small sparks in the air.
As the laser comes into contact with chemical vapors from explosives, it will make a small ignition in the air, which the radar can pick up and analyze to determine which chemicals are present. Some experiments simply emit lasers and detonate bombs when the laser hits.
“There are attempts and actual experiments in the field to put kilowatt-type lasers on a small truck and see if you can just scan the earth, blowing up these things when the laser hits them,” Schlossberg said. “Explosive vapor detection works. It doesn’t work as well as you would like. It will see some explosives, but won’t see others — military explosives that have very low vapor pressures — easily. But help? Yes. Solve the problem completely? No.”
Richard Miles, an expert from Princeton University in laser applications to aerospace, said the problem with that technology at the moment is its imprecision, and the minuscule amounts of chemicals even the most poorly built bombs release into the air.
“These chemicals have signatures which are on the order of parts per trillion of gas molecules to air molecules. So you've got virtually nothing to look at,” Miles said. “And you'd like to be able to come up with a way of being able to detect these things a few hundred feet away so you don't have to get close to them.”
While hand-held laser guns and reliable bomb detectors may not be around for a few more years, a variety of applications for laser technology seen daily came from Air Force-funded labs.
Optical coherence tomography, a technology Schlossberg’s funding helped to invent, is now the standard of care in diagnosing eye disease. Schlossberg said an ophthalmologist who doesn’t have access to an OCT is behind the curve.
“OCT is also becoming enormously important in diagnosing and understanding cardiac disease as well as understanding diseases of the windpipe,” he said. “We're still funding work to study airway injury in windpipes due to smoke inhalation or chemical inhalation. And again, we're using OCT to do that.”
The Air Force also has funded projects related to laser materials processing – one of the biggest current applications of lasers, along with medicine. Lasers are used in microprocessing not only for the production of complex items, but also for the correction of errors in production.
“We funded a great deal of work for many years in microprocessing, making small devices,” he said. “Laser microprocessing is also used, for example, on assembly lines for flat-panel displays, for your LCD television. Those processes are totally automated.
“There are about 600 million of those displays produced a year,” he continued. “And if one of them, in going through the automated line, has something wrong, there's a laser photochemical process that fixes it and then sends it along the line again.”
For more information, visit: www.wpafb.af.mil
- ruby laser
- The optically pumped, solid-state laser that uses sapphire as the host lattice and chromium as the active ion. The emission takes place in the red portion of the spectrum.
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