On 12 January 2015 at 12:34, Attila Kinali <att...@kinali.ch> wrote: > Hi, > > I just stumbled over this [1] nice article by Fritz Riehle that might be > of interest to others as well. > > Attila Kinali > > [1] "Towards a Re-definition of the Second Based on Optical Atomic Clocks", > by Fritz Riehle, 2015 > http://arxiv.org/abs/1501.02068
I had a brief read. Equation 1 made me wonder what could be achieved with a cheap HeNe laser. It should be fairly easy to mix a couple of HeNe lasers on a photodiode and look at the difference frequency between them, so gaining insight into their stability. A quick check on Wikipedia https://en.wikipedia.org/wiki/Helium%E2%80%93neon_laser indicates a spectral width of 0.002 nm. The common 632.8 nm laser has a frequency of 4.7 x 10^14 Hz, or 470 THz. Of course I'm not suggesting a HeNe would provide the stability of cutting edge research laser optical clock, but they are easily within the budget of a hobbyist and could be a bit of fun to try to measure their stability/phase noise. The tricky bit would be getting 470 THz down to 10 MHz, but a cheap and quick experiment would prove whether it is a total waste of time or not. Dave _______________________________________________ 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.
