The third‐order nonlinear optical properties of multilayered films containing 23% by weight of an axially modified silicon phthalocyanine derivative have been measured by degenerate four‐wave mixing at 532 nm with 70 ps full width at half maximum pulses. The average &khgr;(3)of the films measured at (1.33±0.15) ×10−11esu using CS2as a standard and the cubic hyperpolarizability ⟨&ggr;⟩ was calculated at (1.97±0.22)×10−32esu. The degenerate four‐wave mixing signal profile indicates that the films have a response time better than 70 ps. ©1995 American Institute of Physics.