Re: 632.8 nm

[brian whatcott <inet@INTELLISYS.NET>]

At 17:32 4/11/01 -0400, you wrote:
>        "Everyone knows" that the red light from a He-Ne laser is at 632.8
> nm--or is 632.8 nm the vacuum wavelength lambda naught?
>        If so, when we give diffraction and interference problems that
> occur in air, shouldn't we use lambda = 632.8 nm/1.00029 = 632.6 nm?
>                                                Tom Sandin
There is a wonderful trove of data, protocols and discussion available
at the keyboards where we sit, by accessing Google's cache of hits
responsive to 'He-Ne spectrum'.
 One topic that caught my eye was a comparitive method in spectral analysis:
FT vs grating.  I saw some discussion of pulling the
laser frequencies and talk of natural line widths - one was
specified as 0.3A ..er.. 0.03 nm.
I expect this represents some kind of experimental water shed in resolution.


brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!