Professor Keto has worked in the field of multiphoton laser spectroscopy relevant to high pressure discharges, including the development of sensitive techniques for laser induced fluorescence and nonlinear Raman spectroscopy (OHD-RIKES) as a technique with sufficient sensitivity for studies of ions in discharges. His recent research on the electronic states of rare gas clusters has employed multiphoton ionization and time-of-flight mass spectroscopy of clusters. He has also used sychrotron radiation for both excitation and fluorescence spectroscopy of clusters. In the area of nanoparticles, the principal investigator with collaborators Prof. James Brock and Prof. Mike Becker invented (patent pending) and demonstrated a process for generating nanoparticles by laser ablation of microparticles (LAM). Prof. Keto and Prof. Ken Shih have collaborated on the laser spectroscopy of individule nanoparticles and quantum dots using near field microscopy.