Posts tagged advantages of helium neon laser

Output, disadvantage and applications of helium neon laser


I have already explained the construction, working and wavelength of helium neon laser. Today I will explain the output, disadvantage and applications of helium neon laser.

Output: The helium neon laser output is continuous and it lies between 1mW and 50 mW for input of about 5-10 W.

Disadvantage: As internal mirrors are used in He-Ne laser to act as optical resonators, but these mirrors are usually eroded by the gas discharge and have to be replaced.

This problem is eliminated by placing two windows at the ends of the discharge tube at the Beflectrewster angle. For such windows, the light which is polarised in the plane of figure passes through without suffering any reflection loss while light with perpendicular polarisation suffers reflection. Due to use of these windows, the output laser beam is polarised.

Applications: He-Ne lasers are used in research, spectroscopy, holography, communications and weaponry.

Note: In case of any problem in this article or any other physics article, post in the comment section.

After reading this post, you will be able to answer following questions:

  • What is the output of Helium Neon laser?
  • Write the disadvantages of He-Ne lasers.
  • Write the applications of He-Ne laser.
  • Why and how light is polarised in He-Ne laser?

Reference: This article is referred from my authored book “optics and lasers” having ISBN 978-81-272-2948-2

Why helium neon laser is better than ruby laser


Helium neon laser is better than ruby laser or most of the four level lasers are better than three level lasers due to the following reasons:

  • The laser output is continuous in the case of helium-neon laser. But it is in the form of pulse in the ruby laser.
  • Ruby laser requires high power pumping source, whereas Helium-neon laser requires low power pumping source like electric discharge.
  • Efficiency of helium-neon laser is more than ruby laser.
  • The defects due to crystalline imperfections are also present in the ruby laser. But it is not so in the helium-neon laser.

Reference: This article is referred from my authored book “optics and lasers” having ISBN 81-272-2948-2. In case of any doubt, post in the comment section.

Kindly Read This Also :

Note from winnerscience: If you want the e-notes of all the laser  articles that will include the basics of lasers like stimulated absorption, difference between spontaneous and stimulated emission, Einstein  Coefficients, properties and applications of lasers, complete construction and working of lasers like Ruby laser, He-Ne laser, Carbon dioxide laser, Nd:YAG laser, dye laser, semiconductor laser, holography and additional articles of Q-switching and mode locking, then please contact You can post your queries also there.

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