“Laser” is an acronym for “Light Amplification by Stimulated Emission of Radiation”, which describes the theory of laser operation. Albert Einstein published the theoretical basis for the laser in 1917, but it was only in 1960 that the first functioning laser was constructed by Theodore Maiman in California, using a ruby crystal to produce laser light. A Laser is a device that stimulates atoms or molecules to emit light at particular wavelengths and amplifies that light, typically producing a very narrow beam of radiation.

Properties of laser light

Unlike other forms of light, laser light has special properties which make it significantly more effective and dangerous than conventional light of the same power. The laser light particles (photons) are usually:
Monochromatic: consisting of a single wavelength or color.
Coherent: photons are in phase (like marching soldiers).
Collimated: photons are almost in parallel (aligned), with little divergence from the point of origin.

Key terms

• Laser is an acronym for “Light Amplification by Stimulated Emission of Radiation”, which produces a light of a certain wavelength only.