Large and Fast Resonant Third-Order Optical Nonlinearities ofSilicon 2,3-Naphthalocyanine Bis(trihexylsilyloxide)

Abstract

Third-order optical nonlinearities of silicon 2,3-naphthalocyaninebis(trihexylsilyloxide) (SiNc) were measured by femtosecond degeneratefour-wave mixing technique under resonant conditions. The timedependence of the signals indicates that the electronic responsedominates the mechanism. The electronic molecular hyperpolarizabilityγe of SiNc was determined to be as high as 2×10−28 esu,which is the largest value reported so far to our knowledge. Theelectronic third-order susceptibility for a pure SiNc film has beenmeasured to be 4×10−7 esu. The large nonlinear susceptibilitywas discussed in terms of J-type molecular arrangement.