The Basics of Laser (1)

What is laser?

Laser is a light as the result of a technology called Light Amplification by Stimulated Emmission of Radiation. The acronym of this technology became what we acknowledge as laser.

What is the basic theory of laser?

The basic concept of laser was first established by Albert Einstein in The Quantum Theory of Radiation (1917). In a “ground state” condition, atomic energy or molecules are surrounded by electrons. If there is sufficient amount of energy absorbed by the atoms or molecules, then the electron will be positioned in a higher orbit. The electron will be back to the previous orbit while emitting a light spontaneously (spontaneous emission). The unit of this light energy is called photon. In 1960, Maiman successfully invented laser light from ruby crystal.

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How can a laser be produced?

Laser is produced by placing atoms in a cavity which then given an electrical energy. The atoms will convert in an excited state called population inversion. Photon emission is parallel with the same speed, direction, and frequency. On one side of the cavity there is a mirror with total reflection ability, while on the other side there is a partial mirror from which the laser comes out.

What are the active media to produce laser?

Active material (or active media) to produce laser can be in the form of gas (Helium-Neon, carbon dioxide, Argon), liquid (dye in organic solution), solid (alexandrite, neodymium, erbium, chromium), or semi-conductor (gallium arsenide, diode).