Measurement of magic-wavelength optical dipole trap by using the laser-induced fluorescence spectra of trapped single cesium atoms

Based on the multi-level model, we have calculated light shifts for Zeeman states of hyperfine levels of cesium (Cs) 6S(1/2) ground state and 6P(3/2) excited state. The magic-wavelength linearly-polarized optical dipole trap (ODT) for Cs 6S(1/2) |F = 4, m(F) = + 4 (n) over tilde - 6P(3/2) |F' = 5, m(F) = + 5 transition is experimentally constructed and characterized by using the laser-induced fluorescence spectra of trapped single Cs atoms. The magic wavelength is 937.7 nm which produces almost the same light shift for 6S(1/2) |F = 4, m(F) = + 4 (n) over tilde ground state and 6P(3/2) |F' = 5, m(F) = + 5 (n) over tilde excited state with linearly-polarized ODT laser beam. Compared to undisturbed Cs 6S(1/2) |F = 4, m(F) = + 4 (n) over tilde -6P(3/2) |F' = 5, m(F) = + 5 (n) over tilde transition frequency in free space, the differential light shift is less than 0.7 MHz in a linearly-polarized 937.7 nm ODT, which is less than 1.2% of the trap depth. We also discussed influence of the trap depth and the bias magnetic field on the measurement results. (C) 2017 Optical Society of America