3 ms·
Indeed. No mention of Allan deviation, and no links to references. I found this old reference https://ieeexplore.ieee.org/abstract/document/918181/ https://ieee
by spot5010 5y ago
Indeed. No mention of Allan deviation, and no links to references. I found this old reference https://ieeexplore.ieee.org/abstract/document/918181/ https://ieeexplore.ieee.org/abstract/document/918181/
Which claims a short term Allan deviation of 5.4e-16/sqrt(tau) for 1-4s. This is pretty impressive and is comparable to Rb or Cs clocks for short time scales. The best optical clocks achieve something like 1e-18/sqrt(tau). Of course, since the sapphire oscillator is not locked to an absolute reference they drift after a few tens of seconds.
- jjoonathan 5y agoYeah, let's throw some dBc/Hz @ 10kHz offset too for good measure, just to confound the editor :} Aren't stability units grand? Hey, I'm just glad we heard from them before they got body snatched. (Context: since you can drop a low-phase-noise clock into a radar and improve the performance, this area of research is one that the spooky defense types pay active attention to. Many physics departments have legends about projects like this suddenly vanishing into classified status.)
- spot5010 5y agoInteresting. I’m guessing for radar applications it’s really the phase noise above a certain frequency that matters.