An ultrastable laser system at 689 nm for cooling and trapping of strontium

• DOI: 10.1007/s00340-019-7328-3
• Publication Date: 2019-10-26T12:03:56Z
• Authors: Chang Qiao; C. Z. Tan; F. C. Hu; Luc Couturier; Ingo Nosske; Peng Chen; Y. H. Jiang; Bing Zhu; Matthias Weidemüller
• Keywords: Laser linewidth; Finesse

We present a 689-nm cavity-based laser system for cooling and trapping strontium atoms. The laser is stabilized to a high-finesse cavity by the Pound–Drever–Hall technique, exhibiting a frequency stability in the $$10^{-14}$$ range for averaging times up to 100 s. A cavity drift of 8 kHz per day is mapped out and compensated. At short times, the laser exhibits a linewidth of a few kilohertz. With this laser system, we realize a magneto-optical trap of strontium operated on the narrow inter-combination transition yielding sub-microkelvin temperatures, and demonstrate absorption spectroscopy on the strontium inter-combination line.