Author :
Vian, C. ; Rosenbusch, P. ; Marion, H. ; Bize, S. ; Cacciapuoti, L. ; Zhang, S. ; Abgrall, M. ; Chambon, D. ; Maksimovic, I. ; Laurent, P. ; Santarelli, G. ; Clairon, A. ; Luiten, A. ; Tobar, M. ; Salomon, C.
Abstract :
Recent improvements of Bureau National de Me´trologie Syste`mes de Re´fe´rence Temps Espace (BNM-SYRTE) fountains FO1 and FO2 are described. Fractional frequency instabilities of 2.9×10-14τ-12/ for FO1 and 1.6×10-14τ-12/ for FO2 have been demonstrated. A preliminary estimate of the systematic frequency shifts gives an uncertainty of ±7.2×10-16 for FO1 and ±6.5×10-16 for FO2. Furthermore, we present a direct comparison between the two fountains. When a real-time measurement of the collisional shift is included, we observe a stability of the comparison of 5.0×10-14τ-12/ and a frequency difference of δ=4×10-16, well within the combined uncertainties.
Keywords :
atomic clocks; frequency measurement; laser cooling; measurement uncertainty; BNM-SYRTE fountains; Bureau National de Metrologie Systemes de Reference Temps Espace; atomic fountain; cold collisions; collisional shift; fractional frequency instabilities; frequency comparison; frequency difference; frequency shifts; real-time measurement; Atom optics; Atomic beams; Atomic clocks; Frequency estimation; Frequency measurement; Local oscillators; Masers; Optical resonators; Physics; Stability; Atomic fountain; cold collisions; frequency comparison; frequency shifts;
