NONLINEAR-OPTICAL RESPONSE OF FULLERENES

A critical review of nonlinear optical properties of fullerenes is pre sented. We explore structure property relationships for optical nonlin earities of these unusual pi electron systems from two complementary a ngles: (i) to explore the possibility of obtaining structural informat ion from nonlinear optical experiments and (ii) to assess the potentia l of fullerenes, fullerites and their derivatives for the practical no nlinear optical devices. In particular we show that substituted fuller enes form an interesting class of molecules for nonlinear optics. We w ill also show that third harmonic generation of circularly polarised l ight in the solid fullerites should yield some information on the inte rmolecular interactions in these solids. We critically examine the var ious calculations indicating that the screening of the optical fields due to electron-electron interaction may reduce the optical susceptibi lities of these molecules by a large factor and suggest experiments th at may clarify the issue.