Nonlinear optics comparison between results

The intensity of the DFWM signal for the poly(l,6-heptadiyne)s increased linearly with intensity of the incident beam, as shown in Figure 10. From the direct comparison between the intercepts of the V axis of the polymers and the carbon disulfide reference. the values of the polymers were obtained. And also, as the concentration of the polymer solution was increased, the values of the polymers were increased (Figure 11). The third-order nonlinear optical properties were enhanced with an increase in the bulk of the substituents at the 4-position, which is in accord with the bathochromic shift of Amax in the UV—vis spectra. From these results, it was concluded that the incorporation of bulky substituents into the 4-position of 1,6-heptadiynes enforces the TT-conjugated polyene into the more planar conformation. resulting in a red shift and the increment of the values of the polymers. Recently, Schrock... 

A nice example of the influence of laser heating on reorientation was found by Cheung et They observed in a Fabry-Perot resonator filled with a nematic liquid crystal self-oscillation. It was shown that the oscillation resulted from the competition between the fast thermal and slow orientational mechanisms. Thermal processes are fast of course only in comparison with reorientation. In semiconductors similar self-oscillations occur in which heating is the slow process and optical nonlinearities of electronic origin play the role of the fast mechanism. ... 

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