An objective lens for efficient fluorescence detection of single atoms

Yanqiang Guo, Gang Li, Yanfeng Zhang +3 more

V. I. Balykin, Vladilen S Letokhov, V.I. Mishin

Andrew Eddins, D.M. Toyli, Shruti Puri +6 more

Alt, W

We present the design of a diffraction limited, long working distance monochromatic objective lens for efficient light collection. Consisting of four spherical lenses, it has a numerical aperture of 0.29, an effective focal length of 36 mm and a working distance of 36.5 mm. This inexpensive system allows us to detect 8*10^4 fluorescence photons per second from a single cesium atom stored in a magneto-optical trap.

V. I. Balykin, Vladilen S Letokhov, V.I. Mishin +1 more

Guang-Jie Chen, Jun-Jie Wang, Yanan Lv +7 more

The fluorescence collection from single atoms and emitters has been extensively utilized in quantum information and quantum optics research. Here, we investigated the collection efficiency of an objective lens by drawing an analogy between the free-space beam (FSB) and a waveguide mode. We explored how efficiency is influenced by their thermal motion within a dipole trap. Furthermore, we introduce an effective energy fraction ratio to quantify potential imperfections in the focusing of the objective lens. Our results provide valuable insights for optimizing the fluorescence collection in single-atom experiments and highlight the importance of considering realistic experimental conditions when estimating achievable efficiencies.