Question

LASER stands for:
1. Light Amplification by Saturation Emission of Radiation
2. Light Amplified by Saturated Emission of Radiation
3. Light Amplified by Stimulated Emission of Radiation
4. Light Amplification by Stimulated Emission of Radiation

Answer 1

Correct Answer - Option 4 : Light Amplification by Stimulated Emission of Radiation

Laser

• A laser is a device for producing simulated emissions of electro magnetic radiation.
• Laser stands for light amplification by stimulated emission of (electromagnetic) radiation.
• Laser is used in laser printers, barcode scanners, DNA sequencing instruments, laser surgery, and skin treatments, cutting and welding materials, measuring range and speed, etc.
• Luminescence is the spontaneous emission of light by a substance not resulting from heat; or "cold light".

• Dispersion  is defined as the spreading of white light into its full spectrum of colors (in order violet, indigo, blue, green, yellow, orange, and red).
• Radiation that spreads out in different directions from a radiation beam when the beam interacts with a substance is defined as Scattered radiation.

• Stimulated emission, in laser action, is the release of energy from an excited atom by artificial means.
  • Stimulated emission occurs when a photon, with an energy level equal to the energy gap, interacts with the electron.
• Spontaneous emission takes place without interaction with other photons, and the direction and phase are random while Stimulated emission takes place when the excited electron interacts with another photon.