Third-order optical nonlinearities of poly (3-dodecylthiophene) thin films were investigated
using pulsed and continuous-wave (cw) lasers. The nonlinearity measured by the z-scan
method at 532 nm (second harmonic output of the Nd: YAG laser) with nanosecond laser
pulses yielded the value χ (3)∼ 10− 7 esu, similar to the previous experimental results. The
value of the off-diagonal element χ (3) determined from the nanosecond degenerate four-
wave mixing method indicated that the nonlinearity with the pulsed laser input was mainly …

Third-order optical nonlinearities of Rodamin610 (R610) doped polymer thin films with
thicknesses in the range of (171_191) µm, with different concentrations were investigated
using Nd: YAG pulsed laser with nanosecond pulses at 532 nm and continuous-wave (CW)
of diode laser at 650 nm. The optical nonlinearity (nonlinear refraction index, nonlinear
absorption coefficient and third order nonlinear susceptibility) measured by using z-scan
technique: closed and open aperture methods. It was found that the optical nonlinear …