Photoionization
Mon Aug 7 08:46:30 BST 2006
- [quant-ph/0608043]
- Title: Efficient Photoionization-Loading of Trapped Cadmium Ions with Ultrafast Pulses
- Authors: L. Deslauriers, M. Acton, B. B. Blinov, K.-A. Brickman, P. C. Haljan, W. K. Hensinger, D. Hucul, S. Katnik, R. N. Kohn, Jr., P. J. Lee, M. J. Madsen, P. Maunz, S. Olmschenk, D. L. Moehring, D. Stick, J. Sterk, M. Yeo, K. C. Younge, C. Monroe
- Abstract: Atomic cadmium ions are loaded into radiofrequency ion traps by photoionization of atoms in a cadmium vapor with ultrafast laser pulses. The photoionization is driven through an intermediate atomic resonance with a frequency-quadrupled mode-locked Ti:Sapphire laser that produces pulses of either 100 fsec or 1 psec duration at a central wavelength of 229 nm. The large bandwidth of the pulses photoionizes all velocity classes of the Cd vapor, resulting in high loading efficiencies compared to previous ion trap loading techniques. Measured loading rates are compared with a simple theoretical model, and we conclude that this technique can potentially ionize every atom traversing the laser beam within the trapping volume. This may allow the operation of ion traps with lower levels of background pressures and less trap electrode surface contamination. The technique and laser system reported here should be applicable to loading most laser-cooled ion species.
- Comment: This is also applicable to the Yb experiment that I will be working on in Brisbane, so this is good news in that it is a nice experimental technique to use. This is bad news in the sense that the Michigan group already has most of the tools that we will be constructing over the next three years to investigate cooling atomic hydrogen, so they would be able to do the experiment before us if they wanted to. However, their main focus is quantum information so this should not be a problem.
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