Trapping, Cooling, and Photodissociation Analysis of State-Selected H2+ Ions Produced by (3+1) Multiphoton Ionization

We report on the production of cold, state-selected H-2(+) molecular ions in a linear rf trap. The ions are produced by (3 + 1) resonance-enhanced multiphoton ionization (REMPI) of H-2, and sympathetically cooled by laser-cooled Be+ ions. After demonstrating and characterizing the REMPI process, we use photodissociation by a deep UV laser at 213 nm to verify the high vibrational purity of the produced H-2(+) ion samples. Moreover, the large difference between the photodissociation efficiencies of ions created in the v = 0 and v = 1 levels provides a way to detect a v = 0 -> 1 transition. These results pave the way towards high-resolution vibrational spectroscopy of H-2(+) for fundamental metrology applications.