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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.cn

Hua Guan et al., J Laser Opt Photonics 2017, 4:4 (Suppl)

DOI: 10.4172/2469-410X-C1-017