Abstract

The mechanisms involved in the interaction of intense laser beams with the surfaces of transparent optical media have been difficult to study in a controlled manner. We found that a promising experimental approach to this problem is the study of laser-induced particle emission from clean surfaces in an ultrahigh-vacuum environment. An earlier study was reported on ion and electron emission from a number of insulators and wideband gap semiconductors.¹ Multiphoton excitation apparently plays a role in the charged emission. We subsequently obtained evidence that the charged emission is caused by multiphoton ionization that takes place in a flux of emitted neutrals leaving the surface. The neutral emission component is, therefore, more directly related to the laser excitation of the surface.

© 1987 Optical Society of America