Attila I haven't tried that and I suspect the lines are important because that establishes the reference. Now I would also suggest that an experiment like you suggest be tried on a FRS-XXX cheapy Rb. Easily dis-assembled and can be re-assembled back with the lamp. No harm. Paul WB8TSL
On Wed, Feb 21, 2018 at 12:49 PM, Attila Kinali <att...@kinali.ch> wrote: > Moin, > > Has anyone ever tried using a LED instead of a discharge lamp for Rb > standards? > There are quite a few and very cheap 780nm IR LEDs available. They usually > have a line width in the order of 20nm to 50nm (FWHM). This means that they > still need the Rb85 filter, but they would not produce all those spectral > lines > that the discharge lamp has, thus one could get rid of the (not so cheap) > optical filter that Corby uses for the super-5065. > > The one thing I am not sure about is the filter efficiency of Rb85. > Because now the light isn't two discrete lines from the Rb87 lamb > of which one needs to be masked, but a continuous and wide spectrum. > So the Rb85 "notch" filter might not get rid of all the unwanted light > and some of this might depopulate the excited state of the Rb87 > that are in the RF cavity. > > As a side-effect, you also get easier regulation of the light intensity > of the LED, thus potentially less instability due to light-shift variation. > Beside the LED operation being much simpler than that of a discharge lamp > and overall less heat dissipation. > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.