Nematic crystals (NLC) are characterized by large birefringence that spans a broad spectral range, and large susceptibility to ac, dc, and optical fields. Recently, a nonlinear electro-optical effect in dye- or fullerene C60-doped NCL films was discovered. By theory and experiments, the possibility of using low power lasers of a few milliwatts is demonstrated in conjunction with a small dc field to induce persistent realignment of the liquid crystal director axis, and thus a 'stored' refractive index change in these films. An application of the observed effect is holographic grating generation. In a study, it is shown that gratings can be recorded in these NLC films with a nonlinear sensitivity as high as other materials such as doped glasses or photorefractive crystals.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering