Variation of spatial soliton in liquid crystals due change of polarization of the incident laser beam

Abstract

We present experimental evidence obtained in the generation and variation of dark to bright optical spatial solitons due the change of polarization plane of He-Ne laser beam incident in the sample of liquid crystals 5CB doped with methyl red at 0.1% wt inside a cell of 15 μm widths. This work is based in previous papers about the variation of nonlinear refraction index γ in liquid crystals, where we have demonstrated that under certain conditions it is possible to realize inversion of γ, from γ > 0 to γ < 0, by proper adjustment of incident light wave polarization and the theoretical and experimental characterization of spatial solitons. It was possible to observe a clear correlation between the polarization state of incident light and the characteristic profile of dark or bright soliton; we shows here the experimental setup, the results in photographs and their related graphics. The experimental results will open the design of a new system that will generate in the same material a controlled dark or bright spatial optical solitons. We consider this new phenomena very important and as well as its potential technological application in all-optical switching in telecommunications and optoelectronic.