Abstract

The interest in the nonlinear optical (NLO) properties of the fullerenes lies in their unique structure and symmetry which are responsible for the three-dimensional delocalization of π-electrons, a property often associated with enhanced NLO properties in organic materials. At NRL, our studies have focussed on the NLO behavior of pristine films of the fullerenes in the near-infrared^1,2 and visible³ spectral region. Recently, the group at Kentucky succeeded in polymerizing C₆₀ by irradiation of oxygen-free, face-centered-cubic films with visible or ultraviolet light.⁴ It was found that oxygen plays an important role in the photochemistry of C₆₀. We have recently reported on the photo-assisted diffusion of O₂ into solid C₆₀ as well as its photo-oxidation.^5,6 The present paper addresses the effect of altering the electronic/chemical structure, achieved by O₂-doping and photopolymerization, on the NLO properties of C₆₀ and the dynamics of the NLO response.

© 1993 Optical Society of America