Laser

Why in news?

• Army is looking at tapping blockchain, lasers for military use.

About Laser

• “Laser” is an acronym for Light Amplification by Stimulated Emission of Radiation.
• A laser is created when the electrons in atoms in special glasses, crystals, or gases absorb energy from an electrical current or another laser and become “excited.”
• The excited electrons move from a lower-energy orbit to a higher-energy orbit around the atom’s nucleus.
• When they return to their normal or “ground” state, the electrons emit photons (particles of light).
• These photons are all at the same wavelength and are “coherent”, meaning the crests and troughs of the light waves are all in lockstep.
• In contrast, ordinary visible light comprises multiple wavelengths and is not coherent.
• Laser light is different from normal light in other ways as well.
• First, its light contains only one wavelength (one specific color). The particular wavelength of light is determined by the amount of energy released when the excited electron drops to a lower orbit.
• Second, laser light is directional. Whereas a laser generates a very tight beam, a flashlight produces light that is diffuse.
• Because laser light is coherent, it stays focused for vast distances, even to the moon and back.
• There are many applications for laser technology including the following:
  • Laser Range Finding
  • Information Processing (DVDs and Blu-Ray)
  • Bar Code Readers
  • Laser Surgery
  • Holographic Imaging
  • Laser Spectroscopy
  • Laser Material Processing
  • Cutting
  • Engraving
  • Drilling
  • Marking
  • Surface Modification

Prelims Question

Laser technology finds application in which of the following fields?
1.DVD
2.Bar Code Reader
3.Surgery
Select the correct answer using the code given below:
(a)1 and 2 only
(b)2 and 3 only
(c)1 and 3 only
(d)1,2 and 3

 Answer to the Prelims Question