Light Amplification by Stimulated Emission of Radiation or LASER was first developed in the mid 20th century. Stimulating light to a higher energy state and the use of mirrors to reflect specific photons produces what we call laser light. The laser light reflects back using the mirrors and stimulates more electrons--which emits even more photons until you have a concentrated beam.

Properties of Laser Light

Laser light is monochromatic, or all the same color. Laser light is coherent, which means all of the light is in the same phase or the wavelengths are "waving" together. Lastly, laser light is collimated--meaning all of the light is concentrated and moving in the same direction.

Types of Lasers

The type of laser depends on the element used to produce it. There are gas lasers, solid-state lasers, liquid lasers and chemical lasers. Different laser types will produce laser beams of varying intensity and color.