Rubidium and Caesium-Like Doublets of Stripped Atoms

V. K. Prokof’ev, G. Shtandel

Claudia Weber, M. Haas, Shincy John +5 more

Binary mixtures of ultracold atoms are of great interest in the research field of quantum optics and are studied by several groups aiming at different applications. This paper works with rubidium and caesium, which are simultaneously stored in a magnetic trap. Species-selective microwave cooling is used on the rubidium groundstate hyperfine transition. Caesium is sympathetically cooled via elastic collisions with rubidium. When cooling down the mixture to temperatures below 1 muK, below 4 muK we observe strong losses of caesium. Analysing the dynamics of sympathetic cooling, lower limit for the modulus of the rubidium-caesium triplet s-wave scattering length is estimated.

Shu Hotta

Yanhua Wang, Yang Hai-Jing, Du Zhi-Jing +2 more

With a coupling laser locked to caesium 6S 1/2 F g =4–6P 3/2 F e =5 cycling transition and a co-propagating probe laser scanned across 6S 1/2 F g =4–6P 3/2 F e =3, 4 and 5 transitions, a novel scheme for sub-Doppler spectra in Doppler-broadened V-type three-level system is demonstrated by detecting the transmission of the coupling laser through a caesium vapour cell. The Autler–Townes doublet in the sub-Doppler spectra of the coupling laser is clearly observed. The effects of coupling laser intensity on the splitting and linewidth of the Autler–Townes doublet are experimentally investigated and the results agree well with theoretical predictions. Taking the multiple hyperfine levels of caesium atom into account, a brief analysis is presented.

Shu Hotta

A. A. Babin, Michail V. Volkov, Sergey G Garanin +5 more

Abstract Laser oscillation is obtained in caesium and rubidium atoms with wavelengths in the range of 2 – 5.5 μm under pumping to high-lying energy levels. Longitudinal resonant pumping is implemented using the second harmonic of radiation from an optical parametric oscillator. The pump wavelength is tuned over discrete levels from 8P to 10P in caesium atoms and from 6P to 8P in rubidium atoms. The width of the pump radiation spectrum is 12 cm−1. When caesium atoms are pumped, the pump pulse energy is no more than 10 mJ; when rubidium atoms are pumped, it does not exceed 3 mJ. The pulse repetition rate is 10 Hz. The maximum output energy of IR laser radiation upon pumping the 9P3/2 level of caesium atoms is about 100 μJ at a cell temperature of ∼170°C, while the efficiency of pump conversion into radiation energy with a wavelength λ ∼ 3.1 μm turns out to be ∼1 %. For rubidium atoms, an estimate of the output energy of IR radiation gives a value of ∼80 μJ at a cell temperature of 180 °C, which corresponds to an energy efficiency of ∼2.7 %.