Title :
Operation of a compact cesium beam tube: how to improve the stability towards the 10-12 τ-12/ level
Author :
Gurandell, S. ; Hermann, V. ; Barillet, R. ; Cérez, P. ; Théobald, G. ; AÙdoin, C. ; Chassagne, L. ; Sallot, C. ; Delporte, J.
Author_Institution :
BNM-SYRTE, Observatoire de Paris, France
Abstract :
We report the improvement of the frequency stability of a small sized optically pumped Cs beam clock Cs4. This is essentially due to the increase of the signal to noise ratio through detection with a cycling transition. Pumping and detection are respectively performed by means of the (F=4 → F´=4) and (F=4 → F´=5) transitions of the Cs D2 line. An excellent frequency stability is obtained when an extended cavity laser with line-width 400 kHz is used: for τ in the range 1 to 5800s, σy(τ) ≈ 1.5 10-12 τ-12/ instead of 4.10-12 τ -12/ in the basic configuration. Preliminary results indicate that σy(τ) is already improved by a factor 1.4 when a commercial DBR diode laser (line-width less than 1 MHz) is used.
Keywords :
atomic clocks; caesium; distributed Bragg reflector lasers; frequency stability; frequency standards; laser noise; optical pumping; semiconductor lasers; 1 MHz; 1 to 5800 s; 400 kHz; Cs; Cs beam tube frequency standard; Cs4 beam clock; D2 line transitions; DBR laser diodes; atomic clocks; compact cesium beam tube operation; cycling transition detection; distributed Bragg reflector laser diodes; extended cavity laser line-width; frequency stability improvement; optical pumping; optically pumped Cs beam clock; semiconductor lasers; signal to noise ratio increase; time range; Clocks; Frequency; Laser excitation; Laser noise; Laser stability; Laser transitions; Optical beams; Optical noise; Optical pumping; Signal to noise ratio;
Conference_Titel :
Frequency Control Symposium and PDA Exhibition, 2002. IEEE International
Print_ISBN :
0-7803-7082-1
DOI :
10.1109/FREQ.2002.1075931
