WHAT IS LASER?

The word laser stands for Light Amplification by Stimulated Radiation Emission. The laser is an unusual light source. It is quite different from a bulb or strobe light. So much so that Lasers produce a very narrow beam of light. This type of light is useful for many technologies and tools.

How Does the Laser Work?

Light travels in waves and the distance between the crests of a wave is called the wavelength.

Each color of light has a different wavelength. For example; Red light has a longer wavelength than blue light. Sunlight (even light from a light bulb) consists of light of many different wavelengths. Our eyes perceive this mixture of wavelengths as white light.

Lasers differ from other lights in that they do not occur in nature. This particular type of light is created artificially. The light waves that make up lasers have very similar wavelengths. The peaks of the light waves that make up the laser move together sequentially, or in other words, in phase. This is why laser beams are very thin, very bright, and can be focused on a very small spot.

Because laser light stays focused and doesn't spread much (as a flashlight would), laser beams can travel very long distances. They can also transfer a lot of energy into a very small space.

Lasers have many uses. Used in precision machining tools, they can cut diamonds or thick metals. They can also be designed to assist in delicate surgeries. Lasers are also used to record and retrieve information. They are used in communication, transporting television and internet signals. We also see the laser in laser printers, barcode scanners and DVD players in our daily lives. They also help make parts for computers and other electronic devices.

Lasers are also used in instruments called spectrometers. Spectrometers are used to find the contents of the material to be examined. For example; NASA's Curiosity rover uses a laser spectrometer to see what kinds of chemicals are found in certain rocks on Mars.

In space exploration, lasers have been used in spacecraft to study gases in the Earth's atmosphere and to map the surfaces of planets, moons, and asteroids.

Scientists also use lasers to measure distance. By measuring the time it takes for a laser beam to travel to the moon and back, astronomers can tell exactly how far away it is.