Copyright by Kirsten Viering 2006 - Raizen Lab - The University of ...

Figure 3.2: Plot of the AC-Stark shift in Sodium. Numerical values are for a linearly
polarized beam with P=1W and w0=10µm; detailed view around the magic wavelength;
the hyperfine structure belongs to the 3 2 P3/2 state.
Fig. 3.3 shows the AC-Stark shift for circularly (σ + ) polarized light.
A tweezer with circularly polarized light looks less promising compared to
linearly polarized light. The degeneracy of most levels is removed, leading to even
more individual magic wavelengths that are spreaded over a bigger wavelength range.
3.2 Magic wavelength in Rubidium
Using data from Safronova et al. (see also appendix C) we calculated the AC-Stark
shift for Rubidium 87 [19]. Although individual magic wavelengths are found, there
does not exist a wavelength which looks promising for trapping. The steep slope of the
AC-Stark shift around the magic wavelengths near 1400nm leads to a very sensitive
dependance on the trapping wavelength. The energy shift is also strongly dependant
on the magnetic sublevel.
A plot of the AC-Stark shift is shown in fig. 3.4.
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