Selective Loading of Rare Calcium Isotope 43Ca+ using Photo-Ionization
Isamu Morita, U. Tanaka, Shinji Urabe
Rare calcium isotope 43Ca+ ion (0.135%) is the only naturally abundant isotope with hyperfine structure. This isotope is considered an attractive candidate both for an optical frequency standard and for quantum information processing. We report a method to load 43Ca+ ions selectively into a linear Paul trap using a two-step, resonant photo-ionization process. Isotope selectivity is achieved by utilizing the isotope shifts for the resonant 4s2 1S0-4s4p 1P1 transition of neutral calcium. The second non-resonant excitation is achieved by an ultraviolet light emitting diode (LED). The use of an LED is simpler and more economical than using a laser for the second transition. Additionally the laser cooling of 43Ca+ is demonstrated using two ultraviolet-diode lasers and two infrared-diode lasers. Due to the hyperfine structure, the laser requirements for Doppler cooling 43Ca+ are more demanding than for the other isotopes.
The Review of Laser Engineering•Jan 1, 2007•0 citations