物理学报2016，Vol.65Issue(7)：073103-1-073103-6,6.DOI:10.7498/aps.65.073103
铯原子7S1/2态磁偶极超精细常数的测量∗
Measurement of the magnetic dip ole hyp erfine constant Ahfs of cesium 7S1/2 state
摘要
Abstract
Hyperfine-structure (HFS) of atoms results from the interactions between the nuclear magnetic dipole moment and the magnetic field generated by the electrons (related to the magnetic dipole hyperfine constant Ahfs), and between the nuclear electric quadrupole moment and the electric field gradient due to the distribution of charge within atoms (related to the electric quadrupole hyperfine constant Bhfs), so the accurate measurement of HFS is of interest in many fields, including atomic parity nonconservation, tests of fundamental physics, electron-nucleus interaction, and high resolution spectrum and so on. Generally, in order to obtain the atomic spectra, the frequency of laser needs to be scanned over the hyperfine transitions of atoms, so the nonlinear effect from the laser frequency scanning often limits the measurement accuracy of hyperfine splitting. In this paper, we solve this problem, and demonstrate a novel method to measure the hyperfine splitting of atoms. Taking cesium (Cs) for example, based on the Cs 6S1/2–6P3/2–7S1/2 (852.3 nm +1469.9 nm) ladder-type atomic system, three sets of optical-optical double resonance (OODR) spectra are obtained in a room-temperature vapor cell, when the 852.3 nm laser is tuned to the 6S1/2 (F =4)–6P3/2 (F′=4) resonant transition, and the carriers of 1469.9 nm probe laser accompanied with ±1 sidebands from a phase-type electro-optical modulator (EOM) are scanned over the whole 6P3/2–7S1/2 hyperfine transitions. Owing to the Doppler effect, some of the hyperfine transitions in these three sets of OODR spectra overlap with the narrowest linewidth only when the frequency of the signal driving EOM equals the value of hyperfine splitting 7S1/2 state. Using this phenomenon which can effectively avoid the nonlinear influence on the measurement during the frequency scanning process of 1469.9 nm laser, we measure the hyperfine splitting of 7S1/2 state to be (2183.72±0.23) MHz, and the magnetic dipole hyperfine constant Ahfs to be (545.93±0.06) MHz, which are consistent with previously reported experimental results. This technique provides a robust and simple method of measuring hyperfine splitting with a high precision, which is significant to provide the useful information about atomic structure for developing a more accurate theoretical model describing the interaction within an atom.关键词
超精细结构/双共振吸收光谱/电光调制/原子光谱Key words
hyperfine structure/optical-optical double resonance/electro-optical effects/atomic spectra引用本文复制引用
任雅娜,杨保东,王杰,杨光,王军民..铯原子7S1/2态磁偶极超精细常数的测量∗[J].物理学报,2016,65(7):073103-1-073103-6,6.基金项目
国家重点基础研究发展计划(批准号:2012CB921601)、国家自然科学基金(批准号:11104172,11274213,61475091,61227902)和山西省太原市科学与技术研究明星项目(批准号:12024707)资助的课题 （批准号:2012CB921601）
