Recent progress of laser cooling for neutral mercury atom

Kang-Kang Liu; Ru-Chen Zhao; Xiao-Hu Fu; Jin-Meng Hu; Yan Feng; Zhen Xu; Yu-Zhu Wang

doi:10.1117/12.2073328

18 November 2014 Recent progress of laser cooling for neutral mercury atom

Kang-Kang Liu, Ru-Chen Zhao, Xiao-Hu Fu, Jin-Meng Hu, Yan Feng, Zhen Xu, Yu-Zhu Wang

Proceedings Volume 9269, Quantum and Nonlinear Optics III; 92690T (2014) https://doi.org/10.1117/12.2073328
Event: SPIE/COS Photonics Asia, 2014, Beijing, China

Abstract

Mercury is the heaviest stable atom that could be laser cooled, and have a large nuclear charge number. So it has a distinct advantage in quantum precision measurement such as fine-structure constant α and permanent electric dipole moment. Due to its insensitivity of black body radiation, atomic mercury is a good candidate of optical clock. Here we report our recent development of laser cooling of neutral mercury atom. By cooling the mercury source to about -70°C, an ultra-high vacuum system was realized to produce ultracold mercury atoms. The commercial frequency quadrupled semiconductor laser is locked on the cooling transition (¹S₀-³P₁ transition, wavelength of 253.7 nm) by sub-Doppler frequency modulation spectroscopy. By the modification with feed-forward method, the UV laser becomes faster tunable and more stable. A folded beam configuration was used to realize the magneto-optical trap (MOT) because of the shortage of cooling laser power, and the ultracold mercury atoms were observed by fluorescence detection. All of six rich abundant isotopes have been observed, and the atom number is about 1.5×10⁶ with density of 3.5×10⁹ /cm³ for ²⁰²Hg. With optical shutter and the programmable system to control the time sequence, the temperature of ultracold atoms can be measured by time of flight method. To enhance the laser power, a 1014.8 nm fiber laser amplifier was developed, which can work at room temperature. After two stages of frequency doubling, about 75 mW of 253.7 nm UV laser were generated, and the saturated absorption spectroscopy of mercury atom was also observed. More power of UV laser could help to trap more atoms in the future. These works laid a good foundation to realize the mercury lattice clock.

Citation Download Citation

Kang-Kang Liu, Ru-Chen Zhao, Xiao-Hu Fu, Jin-Meng Hu, Yan Feng, Zhen Xu, and Yu-Zhu Wang "Recent progress of laser cooling for neutral mercury atom", Proc. SPIE 9269, Quantum and Nonlinear Optics III, 92690T (18 November 2014); https://doi.org/10.1117/12.2073328

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
9 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Mercury

Chemical species

Ultraviolet radiation

Fiber lasers

Fiber amplifiers

Optical amplifiers

Frequency modulation

Show All Keywords

Keywords/Phrases

Search In:

Publication Years