Sub-picosecond resonant third-order nonlinear optical response of azobenzene-doped polymer film

The dynamics and the sub-picosecond resonant third-order nonlinearity of azobenzene-doped polymer films are investigated by means of transient degenerate four-wave mixing and z-scan techniques. The third-order susceptibility χ(3) and the dephasing time T2 are measured to be (6.3±0.6)×10−12 esu and (1.0±0.1)×10−12 psec, respectively. The creation of a new intermediate state related to a conformational deformation mechanism is supported by experimental observations.