arXiv:physics/0406018 · Physical Review A
Wavelength-dependent ac Stark shift of the S01‐P13 transition at 657nm in Ca
C. Degenhardt, Hardo Stoehr, Uwe Sterr, F. Riehle, Christian Lisdat
Abstract
We have measured the ac Stark shift of the $4{s}^{2}\phantom{\rule{0.2em}{0ex}}^{1}S_{0}--4s4p\phantom{\rule{0.2em}{0ex}}^{3}P_{1}$ line in $^{40}\mathrm{Ca}$ for perturbing laser wavelengths between $780\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and $1064\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ with a time domain Ramsey-Bord\'e atom interferometer. We found a zero crossing of the shift for the ${m}_{S}=0--{m}_{P}=0$ transition and $\ensuremath{\sigma}$ polarized perturbation at $800.8(22)\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. The data was analyzed by a model deriving the energy shift from known transition wavelengths and strengths. To fit our data, we adjusted the Einstein $A$ coefficients of the $4s3d\phantom{\rule{0.2em}{0ex}}^{3}D--4s4p\phantom{\rule{0.2em}{0ex}}^{3}P$ and $4s5s\phantom{\rule{0.2em}{0ex}}^{3}S--4s4p\phantom{\rule{0.2em}{0ex}}^{3}P$ fine structure multiplets. With these we can predict vanishing ac Stark shifts for the $^{1}S_{0}\phantom{\rule{0.2em}{0ex}}m=0--^{3}P_{1}\phantom{\rule{0.2em}{0ex}}m=1$ transition and ${\ensuremath{\sigma}}^{\ensuremath{-}}$ light at $983(12)\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and at $735.5(20)\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ for the transition to the $^{3}P_{0}$ level.