A high stability atomic fountain clock using a cryogenic sapphire interrogation oscillator

Author

Mann, A.G. ; Santarelli, G. ; Chang, S. ; Luiten, A.N. ; Laurent, Ph ; Salomon, C. ; Blair, D.G. ; Clairon, A.

Author_Institution

Dept. of Phys., Western Australia Univ., Nedlands, WA, Australia

fYear

1998

fDate

27-29 May 1998

Firstpage

13

Lastpage

17

Abstract

We describe the operation of the cesium fountain clock in the quantum limited regime, yielding a frequency stability of 5 10^-14τ ^-1/2, where τ is the integration time in seconds. The measured frequency instability varies as 1/√N_at where N_at is the number of detected atoms, up to N_at=6 10⁵. Among the primary frequency standards, this is the best stability ever reported. The noise contribution of the fountain interrogation oscillator has been made negligible thanks to the ultra-low frequency noise in the 0.1-100 Hz Fourier frequency range of a cryogenic sapphire oscillator

Keywords

atomic clocks; caesium; crystal oscillators; electron device noise; frequency stability; frequency standards; low-temperature techniques; sapphire; 0.1 to 100 Hz; Al₂O₃; Cs; Fourier frequency; atomic fountain clock; cryogenic sapphire interrogation oscillator; cryogenic sapphire oscillator; fountain interrogation oscillator; frequency instability; frequency stability; integration time; noise contribution; primary frequency standards; quantum limited regime; stability; ultra-low frequency noise; Atom lasers; Atomic beams; Atomic clocks; Atomic measurements; Cryogenics; Frequency measurement; Laser noise; Oscillators; Q factor; Stability;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control Symposium, 1998. Proceedings of the 1998 IEEE International

Conference_Location

Pasadena, CA

ISSN

1075-6787

Print_ISBN

0-7803-4373-5

Type

conf

DOI

10.1109/FREQ.1998.717871

Filename

717871