what is a laser?

What is a laser?

A laser* is a unique kind of light, more intense and concentrated than anything in nature. Laser light differs from white light (such as sunlight, the light we use in lamps or flashlights) in several ways. Light from most sources spreads out as it travels so that much less of it hits a given area as it moves farther from its source. Traveling as a tight, unbroken beam, the laser light does not disperse as much as it moves away from its origin. Also, while white light is a mix of colored light waves, laser light is monochromatic, having a single wavelength which corresponds to one specific color. Identical wavelengths travel parallel to one another for reinforcement, creating a strong beam that can be focused down to less than 0.001 inch in diameter. Laser light can be controlled very precisely as a steady, continuous beam or in bursts or pulses.

*Light Amplification by Stimulated Emission of Radiation

Light waves from the flashlight are different colors and different lengths; however, the laser light waves are all of the same wavelength and have only one color.

While they can bore holes in the hardest substance of all -- a diamond -- lasers can also perform delicate operations such as surgery.

The early lasers grew out of an experiment in the 1960s when a German scientist, Theodore Maiman, discovered that one could separate and concentrate wavelengths of light. Various materials and designs have been used to do this.