Fig. 1: A superoscillatory trap for a single cold atom.
The trap is a combination of a magneto-optical trap consisting of a pair of anti-Helmholtz coils and six circularly polarized beams red-detuned with respect to the Cs D2-line at 852 nm (green arrows) and a superoscillatory trap beam at the wavelength λ = 1064 nm having a subwavelength hotspot located at the position of the cloud of cold atoms. The superoscillatory mask profile is generated by spatial light modulators, transported to the pupil entrance of a long focal distance microscope objective located outside the vacuum chamber (see Fig. 2a), and focused on the cloud of cold atoms. The image of the superoscillatory hotspot is obtained using a 75× imaging system (see Fig. 2a). The 852-nm fluorescent photons (wiggling arrows) are collected on a photodetector (see Fig. 2a) and used to analyze the performances of the trap.
