Jackie Wallace, age 12, of High Point, N.C., for his question:
HOW DOES A LASER BEAM WORK?
Those in industry can use laser light to weld metal parts together in electronic equipment. Surveyors can use a laser range finder to measure distances in making maps. Doctors use the heating action of a laser beam to remove diseased body tissue. Eye specialists can use the beam to correct a condition called retinal detachment. The laser beam has many uses.
Laser is a device that actually amplifies and strengthens light. It can do many things, including producing a thin beam of light that can carry a signal of many different television pictures at the same time. Laser stands for Light Amplification by Stimulated Emission of Radiation.
Laser light differs from ordinary light in terms of its frequency. The number of vibrations of a light wave per second is much higher with a laser. Ordinary light travels in all directions, while laser beams are narrow and highly directional.
Lasers are used in communications, industry, medicine, military operations and scientific research.
A laser can transmit voice messages and television signals. It is better than ordinary electronic transmitters since the laser operates at a much higher frequency and can carry much more information than radio waves can.
In industry, the laser can be the source of intense heat. A beam, for example, can burn a hole in a diamond. High power lasers are also used to weld metal parts together.
For a retinal operation, the doctor can aim a laser beam into a patient's eye and focus it on the retina. The heat of the beam then "welds" the loose retina into place.
Military men use a laser beam to bounce off a target and thereby determine its distance and speed. There's also much development being made with range finders and gyroscopes.
Light is a form of energy that is released from individual atoms in a substance. Light from the sun or an ordinary light bulb is called incoherent light since it goes in all directions. Excited atoms may be made to release light systematically. This is called stimulated emission and is the main process that takes place in a laser.
How does a laser work? The basic parts include a power source and a light amplifying substance. Stimulated emission results when energy from the power source interacts with excited atoms in the substance.
There are three major kinds of lasers based on their light amplifying substances: solid lasers, gas lasers and liquid lasers.
The laser was developed during the late 1850s. It grew out of earlier studies of microwave amplifying devices. Two American physicists, Arthur Schawlow and C.H. Townes, first proposed the idea of the laser in 1858 and the first one was built in the United States by Theodore Maiman in 1860.