About Lasers-

Light from the sun or an ordinary light bulb is a cacophonous mixture of many different waves. Sunlight contains waves of all frequencies, or colors, and the waves have no specific arrangement with respect to each other. The light from a laser is special. In laser light, the waves are very precisely aligned, crest to crest, trough to trough, and they only occur at a few specific frequencies. This has to do with the way laser light is made.

How We Use Lasers-

Doctors now use lasers in a variety of applications. In particularly bloody operations, the laser can be used as a scalpel with the distinct advantage of cauterizing the incision as it's made. The laser-knife is also perfectly sterile because the only thing touching the patient is light. Tattoos and other specific types of skin markings can be removed with a laser. Using pulsed lasers, an eye surgeon can spot-weld a detached retina to its proper place on the back of the eye without any cutting or discomfort to the patient. By routing the powerful laser light down a fiber, a cardiologist will someday remove the plaque from the inside of arteries, reducing clogging that can lead to heart attacks and strokes

In communication, diode lasers are used to inject light into optical fibers, which act like wires, carrying the light signal to the fiber's other end. Here the signal is received and decoded. These fibers can be 20 miles long. With such systems, telephone companies can simultaneously transmit millions of telephone calls along a single fiber the diameter of a human hair, a huge savings over an equivalent copper-wire system.

Almost everyone now carries a three-dimensional hologram around - on their credit card. Holograms are produced with lasers. To make a hologram, the laser is split into two beams. Both beams are expanded with a lens. After a couple reflections from mirrors, one beam shines directly on the photographic plate, the other shines on the object being photographed. Light reflects from the object and also exposes the plate. The two sources combine and interfere with each other to create the hologram. If you took a hologram and broke it into many pieces, you'd notice that each piece has a complete picture of the object - but each fragment contains a picture from a different viewpoint. The first holograms had to be "played back" a with laser, but it wasn't long before white-light holograms made the scene. Holography can be used by scientists and engineers to make very accurate measurements of motion and shape changes. Research is now being done with X-ray lasers that will allow scientists to take three- dimensional holograms of living cells.

The utility of lasers hasn't been lost on the military. Although it may be a long time before we'll see a Star Trek-type hand held death ray, experimental lasers capable of shooting down missiles have been developed that can be mounted on a tank or plane. Laser guided missiles follow a spot of laser light placed on the target by a soldier on the ground, or from a plane in the air. These deadly missiles have pinpoint accuracy as we saw during Desert Storm. Of course, Laserium is dedicated to the peaceful, safe, and artistic use of lasers.

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