A new organic material 4-hydroxy-ethyl-phenyl-porphyrin-3-propionate was investigated due to its favorable nonlinear absorptive and refractive properties using a modified time-resolved pump-probe system with phase object at 532 nm under picosecond pulse excitation. A five-level model was used to explain the optical nonlinearity of the sample. With the corresponding fitting program, the nonlinear coefficients of the sample were obtained.
The nonlinear refractive response of a copper phthalocyanine film fabricated by the electro-deposition is
investigated by a modified top-hat Z-scan with 19 picoseconds pulse at wavelength of 532 nm. Compared to the top-hat
Z-scan, the curve of modified top-hat Z-scan for the nonlinear refraction shows a single peak rather than a peek-valley
curve. Furthermore, the sensitivity of this new technique can be more than two orders of magnitude enhanced. The
results show that the film has obvious response of nonlinear refraction. The theoretical simulation fit well with