Abstract

This paper is addressed to the question of surface states on the (111)-surface of BaF₂, which can serve as a model for other divalent ionic crystals. The goal is to prove that surface states, which are energetically located in the middle and upper half of the bandgap, play a decisive role in the desorption process. They can either absorb single photons which results in local heating and thermal desorption or, more of interest in this context, they can resonantly enhance multiphoton absorption.

© 1987 Optical Society of America