laser Antima mehta

1. Helium-neon laser

2. Helium-neon laserHelium-neon laser

3. • :: The Helium-Neon laser was the first continuous laser. It was invented by Javan et. al. in 1961.The Helium-Neon laser was the first continuous laser. It was invented by Javan et. al. in 1961.
But how did Javan manage to do this? This shows that it is no coincidence thatBut how did Javan manage to do this? This shows that it is no coincidence that JavanJavan first He-first He-
Ne laser oscillated at a Wavelength of 1.5Ne laser oscillated at a Wavelength of 1.5μμm, since the amplification at this wavelength ism, since the amplification at this wavelength is
considerably Higher than the 632 nm line which is reached at what is now commonly known asconsiderably Higher than the 632 nm line which is reached at what is now commonly known as
the red line, which was made to oscillate only one year later by White andthe red line, which was made to oscillate only one year later by White and RigdenRigden. The similarity. The similarity
between the manufacturing techniques of He-Ne lasers and electron valves helped in the massbetween the manufacturing techniques of He-Ne lasers and electron valves helped in the mass
production and distribution of He-Ne lasers.. It is now clear that He-Ne lasers will have toproduction and distribution of He-Ne lasers.. It is now clear that He-Ne lasers will have to
increasingly compete with laser diodes in the future. But He-Ne lasers are still unequalled as farincreasingly compete with laser diodes in the future. But He-Ne lasers are still unequalled as far
as beam geometry and the purity of the modes are concerned. Laser diodes will have to beas beam geometry and the purity of the modes are concerned. Laser diodes will have to be
improve to a great extent before they pose a serious threat to helium-neon laserimprove to a great extent before they pose a serious threat to helium-neon laser
•
19611961 ??
--
1.51.5μμmm ,,
RidgenRidgen ,, ,, 632632
----....
----

4. • --,, HeNeHeNe ,,
--
, 632.8, 632.8
(())

5. --
• 8080 1.5cm1.5cm
11 20:20: ,, ,, 55 ,, , 1, 1 ((5050 ))
10001000 5-1005-100
,, 1%1% ,,
HeNeHeNe 0.50.5 1515 ,, 11 100100 ,,

7. --
• atoms.Theatoms.The
, 21S1, 21S1 21S0,21S0, 11S011S0 metastablemetastable ,, ,,
,, NENE ,, ,, NeNe

9. --
• HeNeHeNe
((),), collisionally 21Socollisionally 21So * (21So),* (21So),
(()) * (21So)* (21So) unexcited Neunexcited Ne , NE * (3s2), NE * (3s2) ,, NeNe unexcitedunexcited ,, --,,

10. • NeNe (2P)(2P) metastablemetastable (3s)(3s) ,, 632632
,, NeNe 632nm632nm
(2P)(2P) (3s)(3s)
,,
NeNe 1s1s NeNe radiationlessradiationless

11. --
• --
-- 33
--,,

12. Helium-neon laser