Re: green laser question

[John Gastineau <john@GASTINEAU.ORG>]

> Can Helium-Neon be made to lase at other than the usual wavelength?
>
> The Sargent Welch catalog has a green laser (550 nm) that they claim is a
> solid state diode laser (this makes sense to me).  But the company that
> makes it, Metrologic, has a similar picture in its catalog but specifically
> claims (twice) that it is a green _He-Ne_ laser.  Somebody is confused, and
> it could be me.

Yes, you can make a HeNe operate in the green region (a so-called GreNe) as
well as in the infrared. This takes careful design of the dielectric mirrors
so that the red line does not oscillate in the laser cavity. Usually such
HeNes are more expensive and less powerful than a red laser of similar design.

If you look at an energy level diagram for neon you'll see several transitions
that will achieve inversion that are at wavelengths other than 632nm.

JEG
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John E. Gastineau                                 john@gastineau.org
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