Spatially resolved photoionization of ultracold atoms on an atom chip
Physical Review A (Atomic, Molecular, and Optical Physics), (2007)DOI: 10.1103/physreva.75.063605
Abstract
We report on photoionization of ultracold magnetically trapped Rb atoms on an atom chip. The atoms are trapped at 5 µK in a strongly anisotropic trap. Through a hole in the chip with a diameter of 150 µm, two laser beams are focused onto a fraction of the atomic cloud. A first laser beam with a wavelength of 778 nm excites the atoms via a two-photon transition to the 5D level. With a fiber laser at 1080 nm the excited atoms are photoionized. Ionization leads to depletion of the atomic density distribution observed by absorption imaging. The resonant ionization spectrum is reported. The setup used in this experiment is suitable not only to investigate mixtures of Bose-Einstein condensates and ions but also for single-atom detection on an atom chip.