| Popis: |
Photorefractive polymer composites based on polymers with a high glass transition temperature, such as aromatic polyimide, Tg = 240 °C, polyvinylcarbazole, Tg = 200 °C, in which the random distribution of photosensitizers and nonlinear optical chromophores as dopants are “frozen” are discussed. In the case of the random distribution of chromophores, the third-order electric susceptibility has a nonzero value. Therefore, the nanosized structures having the high third-order polarizability due to an extended conjugated-bond system that is the carbon nanotubes should be used. The use of the same chromophores as the spectral sensitizers allowed us to develop polymer composites with photorefractive sensitivity in the near-IR region, at 1064 and 1550 nm. Photoelectric, charge transport, nonlinear optical, and photorefractive properties were investigated and results are presented in this chapter. The net two-beam coupling gain coefficients of 110 cm−1 at 1064 nm and 27.4 cm−1 at 1550 nm were obtained. |
