A novel experimental technique has been developed to observe a trace of optical absorption of free mass-selected ions. The technique combines a linear radio-frequency ion trap with a high-finesse optical cavity to perform cavity ring-down spectroscopy (photon-trap spectroscopy for generality), where the storage lifetime of photons in the cavity provides a sensitivity high enough to probe the trapped ions. Absorption spectra of the manganese ion Mn+ are presented, showing hyperfine structures for the P 2,3,4 7 S37 transitions in the ultraviolet range. Implementation of a solenoidal magnet allows us to observe the Zeeman splitting and the Faraday rotation as well.
All Science Journal Classification (ASJC) codes