Recurrence spectroscopy of potassium near ionization using laser diodes

In this investigation recurrence spectra of potassium are acquired using 405 and 980 nm laser diodes. Atoms were excited to Rydberg-Stark states (n approximate to 70) resonantly via the 5p(3/2) state and recurrence spectra were obtained near the classical ionization threshold. The data suggest that the outgoing distribution of electrons is more symmetric in potassium than in hydrogen or sodium and that phase shifts incurred by the electron wave function as it passes through the atomic core cause regular destructive interference within the recurrence spectra.