We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a magneto-optical trap. This is achieved by adding a depumping laser tuned to the $^{3}P_{1}\ensuremath{\rightarrow}^{3}S_{1}$ (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65% for the bosonic isotopes and up to 30% for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, intensity, and beam size. To understand the results, we develop a one-dimensional rate equation model of the system, which is in good agreement with the data. We discuss the use of other transitions in strontium for accelerated trap loading and the application of the technique to other alkaline-earth-like atoms.We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a magneto-optical trap. This is achieved by adding a depumping laser tuned to the $^{3}P_{1}\ensuremath{\rightarrow}^{3}S_{1}$ (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65% for the bosonic isotopes and up to 30% for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, intensity, and beam size. To understand the results, we develop a one-dimensional rate equation model of the system, which is in good agreement with the data. We discuss the use of other transitions in strontium for accelerated trap loading and the application of the technique to other alkaline-earth-like atoms.

arXiv:1508.05405Physical Review AOct 26, 20159 citations

Analyzing a single-laser repumping scheme for efficient loading of a strontium magneto-optical trap

Fachao Hu, Ingo Nosske, Luc Couturier +6 more

We demonstrate enhanced loading of strontium atoms into a magneto-optical trap using a repumping scheme from the metastable state via the doubly excited state $5s5p{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{2}\ensuremath{\rightarrow}5{p}^{2}{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{2}$ at $481\phantom{\rule{3.33333pt}{0ex}}\mathrm{nm}$ . The number of trapped atoms is increased by an order of magnitude. The frequency and intensity dependence of the atom number enhancement, with respect to the nonrepumping case, is well reproduced by a simple rate equation model, which also describes single-laser repumping schemes reported previously. The repumping scheme is limited by a weak additional loss channel into the long-lived $5s5p{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{0}$ state. For low repumping intensities, the signature of a halo formed by magnetically trapped atoms in the metastable state is found.We demonstrate enhanced loading of strontium atoms into a magneto-optical trap using a repumping scheme from the metastable state via the doubly excited state $5s5p{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{2}\ensuremath{\rightarrow}5{p}^{2}{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{2}$ at $481\phantom{\rule{3.33333pt}{0ex}}\mathrm{nm}$. The number of trapped atoms is increased by an order of magnitude. The frequency and intensity dependence of the atom number enhancement, with respect to the nonrepumping case, is well reproduced by a simple rate equation model, which also describes single-laser repumping schemes reported previously. The repumping scheme is limited by a weak additional loss channel into the long-lived $5s5p{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{0}$ state. For low repumping intensities, the signature of a halo formed by magnetically trapped atoms in the metastable state is found.

arXiv:1812.01258Physical Review AMar 27, 201917 citations

Progress towards isotope-dependent trapping of strontium

Roger Ding, Francisco Camargo, J. D. Whalen +3 more

Bulletin of the American Physical SocietyMay 25, 20160 citations

A new optical trap and repump system for ultracold Strontium

Yanyan Huang, Mi Yan, B. J. DeSalvo +1 more

Bulletin of the American Physical SocietyJun 6, 20130 citations

481\phantom{\rule{3.33333pt}{0ex}}\mathrm{nm}

. The number of trapped atoms is increased by an order of magnitude. The frequency and intensity dependence of the atom number enhancement, with respect to the nonrepumping case, is well reproduced by a simple rate equation model, which also describes single-laser repumping schemes reported previously. The repumping scheme is limited by a weak additional loss channel into the long-lived

5s5p{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{0}

state. For low repumping intensities, the signature of a halo formed by magnetically trapped atoms in the metastable state is found.