What Is A Laser?

A LASER is an electo-optical device that produces a very intense beam of light that is typically concentrated into a single wavelength and frequency that is characteristic of the material producing it.  LASER light can only be generated by chemical materials that have the capability of undergoing LASING.  The word LASER is an anagram that gives a very accurate description of what a LASER is and how it works; it stands for the Light Amplification by the Stimulated Emission of Radiation.    To produce it, you first start with LASER producing material. It is irradiated with high energy directed to a very specific located and concentrated.  The energy from this bombardment is absorbed by uniquely characteristic electron rings within the quantum mechanical electron cloud described by Werner Heizenberg and Neils Bohr.  As these electrons absorb energy they are elevated to an excited quantum mechanical state.  If energy continues to be added to the system it will eventually reach a point in which it cannot add any more.  The electron will drop down to its normal, stable state at this point and will simultaneously discharge all the contained energy in a single, very short and concentrated burst of light/energy.    A few of the very special and unique properties of this LASER  light are:  1) the light has the property of being extremely cohert, i.e., the light rays are nearly perfectly parallel from the time they leave the source, on out into space for hundreds, even thousands of miles without losing its coherence.  In addition, the light can be colored, colorless, opaque, or even invisible to our eyes, depending on the frequency of the light emitted.

A laser is a device that produces a beam of light and makes the beam more intense. A laser beam is very exact. It can travel a long distance without spreading out and losing its power.

Laser light is unlike sunlight or light from a light bulb. To understand the difference, think of a crowded city street. Thousands of people are walking along the sidewalk. Their clothes are of many different colors. They are walking in many different directions. Now think of a marching band in a parade. Everyone is wearing a uniform of the same color. They are all walking in the same direction, in step with one another.

Sunlight and light from lamps are like the crowd on the sidewalk. They are made up of many colors—all the colors of the rainbow. They spread out in all directions from their source. Laser light is like the marching band. It is light of a single color. It travels in a beam. It spreads out very little, even when traveling through outer space.