Abstract
Buckminsterfullerene exhibits a large ultrafast third-order nonlinear optical response. Degenerate four-wave-mixing measurements in -benzene solutions were performed using 50-psec pulses at 1.064 μm. The magnitude of the nonlinear susceptibility per molecule is ‖γ‖=1.5× and of the same size as that observed in polydiacetylene. In contrast to conjugated polymers, however, a dominant positive real part of the nonlinearity is found, 3 times larger than the imaginary component. The nonlinear response can be described within the model of a free electron in a spherical box, confirming the complete delocalization of electrons on the molecule.
- Received 22 May 1991
DOI:https://doi.org/10.1103/PhysRevLett.67.1423
©1991 American Physical Society