Absolute and relative stability of an optical frequency reference based on spectral hole burning in Eu3+:Y2SiO5.
We present and analyze four frequency measurements designed to characterize the performance of an optical frequency reference based on spectral hole burning in Eu3+:Y2SiO5. The first frequency comparison, between a single unperturbed spectral hole and a hydrogen maser, demonstrates a fractional frequency drift rate of 5×10(-18)  s(-1). Optical frequency comparisons between a pattern of spectral holes, a Fabry-Pérot cavity, and an Al(+) optical atomic clock show a short-term fractional frequency stability of 1×10(-15)τ(-1/2) that averages down to 2.5(-0.5)(+1.1)×10(-16) at τ=540  s (with linear frequency drift removed). Finally, spectral-hole patterns in two different Eu(3+):Y2SiO(5) crystals located in the same cryogenic vessel are compared, yielding a short-term stability of 7×10(-16)τ(-1/2) that averages down to 5.5(-0.9)(+1.8)×10(-17) at τ=204 s (with quadratic frequency drift removed).
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305, USA.
David R
DR
Leibrandt
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305, USA.
Michael J
MJ
Thorpe
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305, USA.
Chin-Wen
CW
Chou
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305, USA.
Tara M
TM
Fortier
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305, USA.
Scott A
SA
Diddams
National Institute of Standards and Technology, 325 Broadway Street, Boulder, Colorado 80305, USA.
Till
T
Rosenband