Ultranarrow absorptive spectral line induced by microwave field

This paper investigates the absorptive spectral lines of four-level atomic system driven by a coupling, probe and microwave fields. Due to the perturbation of the microwave field, the original electromagnetically induced transparency is changed to electromagnetically induced absorption and the absorptive spectral line can be very narrow. This ultranarrow spectral line has potential applications to the microwave atomic frequency standard and the measurement of very weak magnetic field.

Analytical solution of microwave transition spectral lines for ^(87)Rb atoms in a Hanle configuration

This paper theoretically investigates the microwave transition spectrum of STRb atomic D1 line with specially prepared atomic state in a Hanle configuration. The approximate analytical results have shown that the 0-0 transition spectral line has the highest contrast and can be applied to microwave frequency standards.

正交偏振探测技术型脉冲光抽运原子钟研究进展

介绍了本课题组新概念小型化星载原子钟的研究进展。利用已有的脉冲光抽运技术和独立提出的正交偏振探测技术,将原子钟的钟跃迁信号的对比度从一般吸收法的30%提高到将近100%。该方法主要探测的是光的振幅和相位的总变化,因而能有效提高探测灵敏度和信噪比,从而提高频率稳定度。实验结果表明,正交偏振探测技术原子钟的原子频率稳定度比相同条件下吸收法原子钟的原子频率稳定度提高一个量级;而且在实验的基础上,物理系统的温度稳定度、磁场电流稳定度和激光光强稳定度都能够提高一个量级,正交偏振探测技术原子钟的秒稳能达到1×10-13,天稳能优于1×10-15,将来可能进一步发展并取代氢钟。

High contrast transparent ramsey fringes using microwave pulses interaction with atomic coherent state in warm rubidium vapor

High contrast transparent Ramsey fringes are observed using double microwave pulses interaction with the prepared atomic coherent state in a warm STRb vapor with mixture buffer gases in a closed cell. The Ramsey fringes are generated by the pulsed technique, a strong coupling light pulse and a weak signal light pulse are applied to prepare the atomic coherent state, followed by the application of double microwave pulses to interact with the atomic coherent state. Afterwards, the light pulses are applied again with weaker intensity and detecting the signal transmission is delected. The central line of the transparent Ramsey fringes has narrow linewidth of 125 Hz and high contrast of 21%. The light shift is dramatically reduced since the interrogating process is not involved the light field, and the cavity pulling effect is negligible due to the low Q requirement, which is promising for building small, compact, and stable atomic clocks.

Microwave excited optical transparency enhancement resonances in Hanle-EIT configuration

We report an experimental observation of the optical transparency enhancement resonances in Hanle- electromagnetically induced transparency （EIT） configuration with a microwave field excitation. In this experimental system, a strong control field and a weak probe field form three-level A-type configurations of EIT. The fourth level is coupled by an additional microwave field. With the microwave field excitation, the probe field undergoes a process of absorption to transparency when the probe field decreases. Compared with the EIT effect, this result indicates optical transparency enhancement. A simple theoretical model and a numerical simulation are presented to explain the observed experimental results. The applications of these optical features are also discussed.

利用磁光效应获得超高对比度的原子钟跃迁谱线

由中科院量子光学重点实验室王育竹院士领导的新型星载原子钟课题组，在2012年12月15日出版的国际学术期刊（《光学快报》上，首次报道了利用基于磁光旋转效应的正交偏振探测技术探测气泡式铷原子钟的钟跃迁信号，获得了对比度高达90％的超高对比度钟跃迁信号，抑制了散弹噪声，压制了激光振幅和相位起伏的噪声，极大地提高了钟跃迁信号的信噪比和原子钟中短期频率稳定度。