Non-medical lasers: everyday life in a new light - Food and Drug Administration regulates lasers used in scanning systems, compact disc players, light shows, computer printers and telephone cables - includes article on monitoring of laser safety

FDA Consumer, July-August, 1991 by Rebecca D. Williams

And in photography and art, lasers can produce three-dimensional photographs called holograms. You may have seen them on your credit cards--banks use holographic emblems to protect against counterfeiting. Scientists say someday holograms will give us three-dimensional pictures of everything from molecules to city streets. Perhaps we'll even watch three-dimensional television on table tops.

Measuring Up

Because of their precision, lasers have offered a new way of taking measurements.

With lasers, scientists can calculate the distance to the moon more accurately than ever before. In 1969, astronauts placed an object on the lunar surface that can reflect a laser beam back to its precise origin on Earth. Using a 4-billion-watt pulse laser, scientists now measure the distance to the moon to within 6 centimeters, or 2.4 inches.

Lasers can also take small measurements, such as the vibration of atoms and molecules, the frequency of light, and the amount of trace pollutants in air and water.

Lasers for the Future

Lasers have the potential to generate clean, powerful energy from the world's most abundant natural resource--sea water--using the same process that fuels the sun and stars. Called fusion, the process involves compressing atoms together to release energy.

Fusion on the sun is produced by tremendous gravity forcing atoms together. On Earth, scientists can briefly produce fusion with lasers. At the Lawrence Livermore National Laboratory in Livermore, Calif., scientists have developed a powerful laser called NOVA. In a fraction of a second, this laser can heat a tiny pellet of frozen hydrogen several million degrees. The heating is so fast that the atoms don't have a chance to escape as vapor. Instead, they compress and implode. For a brief instant, fusion results. A mini-star is born.

So far, however, the laser is not powerful enough to produce sustained fusion, and the technology is still decades away.

Scientists already know how to split an atom to produce energy. Called fission, the reaction is used in nuclear power plants and atomic bombs. Unlike fission, laser-generated fusion would produce few hazardous wastes--some scientists say none at all.

As the laser industry grows, scientists continue to discover new applications for this special light. Some speculate the next generation of scientists will use lasers to explore other star systems or fuel spaceships far into the galaxy.

For now, however, the future scientists in Donaldson's optics class have fun with laser basics.

"Lasers are the most 'sexy' thing, I guess you could say, that we do," says the science teacher. "They're beautiful scientifically because the work is so clean and clear and measurable. Plus, it's just fun to do.

"I appreciate the scientific part of it," Donaldson adds. "The kids appreciate the fun part."

Rebecca D. Williams is a staff writer for FDA Consumer.

How FDA Monitors Laser Safety

FDA regulates all kinds of lasers, from the ones used in surgery to those found in supermarket checkout scanners. The agency has authority to regulate them under the Radiation Control for Health and Safety Act and the Medical Device Amendments to the federal Food, Drug, and Cosmetic Act.