“…On the other hand, nonharmonic oscillation of π-conjugated electrons, which are loosely tied to the molecular skeleton, is responsible for NLO response in organic NLO materials under the irradiation of high power laser light . In addition, thermal NLO response, i.e., thermally induced nonlinear refractive index, is well investigated when high-power CW laser light is illuminated, for example, to the metal colloidal nanoparticle . As a matter of course, both the much large NLO susceptibility and ultrafast optical response time are required at the same time so as to realize the high performance of optical and/or photonic device applications in the near future, ,, for example, optical wiring, optical transistors, random lasing, optical memory, and all optical computing systems .…”