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conferenceseries
.com
Volume 4, Issue 4 (Suppl)
J Laser Opt Photonics, an open access journal
ISSN: 2469-410X
Optics 2017
November 15-17, 2017
November 15-17, 2017 | Las Vegas, USA
8
th
International Conference and Exhibition on
Lasers, Optics & Photonics
A comparison of two
40
Ca
+
single ion optical clocks at 5×10
-17
Hua Guan, Yao Huang
and
Kelin Gao
Chinese Academy of Sciences, China
A
comparison of two optical clocks and a detailed study of the systematic frequency shifts of each
40
Ca
+
single-ion optical clock
were carried out in WIPM. A Ti:sapphire laser at 729 nm is frequency stabilized to an ultra-stable ultra-low thermal expansion
coefcient (ULE) cavity by means of Pound-Drever-Hall method. 1 Hz linewidth and 2×10
−15
frequency stability at 1-100 s is realized.
Which is used for the probe of
40
Ca
+
optical transition. After compensating for the micromotion, the two optical clocks both reach an
uncertainty level of a few parts in 10
−17
. The dominant source of uncertainty is the blackbody radiation (BBR) shift after minimizing
the micromotion-induced shifts. The BBR shift is evaluated by controlling and measuring the temperature at the trap center. With a
measurement over one month, the frequency difference between the two clocks is measured to be 3.2 (5.5)×10
−17
. Due to improvement
of the clock laser and better control of the optical and electromagnetic feld geometry and the laboratory conditions, a fractional
stability of 7×10
−17
in 20,000 s of averaging time is achieved. The absolute frequency of the
40
Ca
+
4s
2
S
1/2
- 3d
2
D
5/2
clock transition is
measured to be 411 042 129 776 401.7 (1.1) Hz, with a fractional uncertainty of 2.7 × 10
−15
using the GPS satellites as a link to the SI
second.
Biography
Hua Guan has completed his PhD from Wuhan Institute of Physics and Mathematics (WIPM), The Chinese Academy of Sciences (CAS) and he visited NIST Boulder twice
between 2008-2010. He is a Professor of WIPM. His major is Precision Measurement Physics. And his research interests are single-ion optical clocks and trapped ion
precise spectroscopy. He has published more than 20 papers, including
Phys. Rev. Lett., Phys. Rev. A, Appl. Phys. B, Rev. Sci. Instum.
etc.
guanhua@wipm.ac.cnHua Guan et al., J Laser Opt Photonics 2017, 4:4 (Suppl)
DOI: 10.4172/2469-410X-C1-017