Autoionizing states of zirconium by three-photon polarization spectroscopy

In order to study autoionizing states of zirconium, we performed three-photon polarization spectroscopy. Three dye lasers were used as atomic excitation sources. The first two dye lasers charged with rhodamine 570 were pumped by the second harmonics of a Nd:YAG laser. Atoms in the high-lying even parity levels were excited to autoionizing states and ionized by scanning the third dye laser, which was pumped by the third harmonics of the Nd:YAG laser.