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Register a new userResonant photo-ionization of Yb+ to Yb2+
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We demonstrate the controlled creation of a $mathrm{^{174}Yb^{2+}}$ ion by photo-ionizing $mathrm{^{174}Yb^+}$ with weak continuous-wave lasers at ultraviolet wavelengths. The photo-ionization is performed by resonantly exciting transitions of the $mathrm{^{174}Yb^+}$ ion in three steps. Starting from an ion crystal of two laser-cooled $mathrm{^{174}Yb^+}$ ions localized in a radio-frequency trap, the verification of the ionization process is performed by characterizing the properties of the resulting mixed-species ion-crystal. The obtained results facilitate fundamental studies of physics involving $mathrm{Yb^{2+}}$ ions.
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We discuss and measure the phase shift imposed onto a radially polarized light beam when focusing it onto an $^{174}text{Yb}^{+}$ ion. In the derivation of the expected phase shifts we include the properties of the involved atomic levels. Furthermore, we emphasize the importance of the scattering cross section and its relation to the efficiency for coupling the focused light to an atom. The phase shifts found in the experiment are compatible with the expected ones when accounting for known deficiencies of the focusing optics and the motion of the trapped ion at the Doppler limit of laser cooling.
We address the concept of direct multiphoton multiple ionization in atoms exposed to intense, short wavelength radiation and explore the conditions under which such processes dominate over the sequential. Their contribution is shown to be quite robust, even under intensity fluctuations and interaction volume integration, and reasonable agreement with experimental data is also found.
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