Define about the set-up of Helium-Neon Laser.

The laser radiations along with higher coherence, higher directionality and higher monochromacity can be obtained from this. But, the output power is usually few mW. The fundamental setup of Helium-Neon laser is demonstrated into the given figure:

Helium-Neon Laser

In actually, what occurs is that

e + He →He* + e

 He* + Ne →He + Ne*

Ne* →Ne + hν(laser photon)

Through the electrical discharge into the gas tube, the laser action happens because of population inversion.