Resonant optical nonlinearity of fullerenes in free-standing polymethyl methacrylate films

Abstract

An experimental investigation was reported involving both the preparation of films of polymethyl methacrylate (PMMA) doped with fullerenes and the observation of resonant χ(3) at a wavelength of 608 nm. By conducting the degenerate four-wave mixing experiment and measuring irradiance-dependent transmission, the third-order nonlinear susceptibility of the films were determined to be of the order of 10-10 esu, and it was governed by its imaginary part. The observed nonlinear susceptibility was found to be primarily caused by excited-state absorption by comparing with the tight-binding theory and excited-state absorption model.