Photoabsorption spectra ofs 1-electron metal clusters

Collinear laser/molecular beam photodepletion spectroscopy has developed into a powerful tool for the determination of electronic absorption in neutral alkali metal clusters free of perturbing matrix effects. We briefly discuss the method, present data on selected Na _x and Li _y Na _x?y ,x≤20, contrast measurements with the known optical response of larger colloidal metal clusters, compare microcluster spectra with the predictions of various models and speculate on future experimental and theoretical developments in this field.