Photoabsorption and Magneto-Optical Spectroscopy of Mass-Selected Atomic and Cluster Ions Stored in an Ion Trap

Abstract

A novel experimental technique is presented for optical absorption spectroscopy, magneto‐optics (Zeeman and Faraday effects), and spin polarization of free atomic and cluster ions. In this technique, mass‐selected ions stored in an ion trap are interrogated by photons trapped in a cavity. The storage lifetime of photons in the cavity provides extremely high sensitivity in absorption and polarization‐rotation measurements (photon‐trap spectroscopy: an extended scheme of cavity ring‐down spectroscopy). The atomic ion of manganese (Mn+) and a silver cluster ion (Ag9+) are studied including the effects of temperature and magnetic field.