Photoinduced surface relief grating (SRG) formation on azopolymer films is discussed precisely using a fluid mechanics model which takes depth dependence of photoinduced driving force and velocity distribution in the film surface into account. Formulation for the SRG dynamics is derived analytically as a function of film thickness and interference wave number. The film thickness dependence of diffraction efficiency, which is observed experimentally, agrees well with the theoretical value in the entire range of film thickness. The dependence of SRG driving force on interference wave number is also discussed in terms of the experimental data using proposed model.

Photocontrol of molecular alignment is an exceptionally-intelligent and useful strategy. It enables us to control optical coefficients, peripheral molecular alignments, surface relief structure, and actuation of substances by means of photoirradiation. Azobenzene-containing polymers and functionalized liquid crystalline polymers are well-known photocontrollable materials. In this paper, we introduce recent applications of these materials in the fields of mechanics, self-organized structuring, mass transport, optics, and photonics. The concepts in each application are explained based on the mechanisms of photocontrol. The interesting natures of the photocontrollable materials and the conceptual applications will stimulate novel ideas for future research and development in this field.

Electron injecting properties have been studied for one of polyquinoxaline (PQx) derivatives. PQx was clarified to be an excellent electron injecting material for electroluminescent (EL) device because it has many advantageous properties such as high electron affinity, good thermal stability, good processability, and sufficiently low refractive index. On the other hand, since poly(p‐phenylenevinylene) (PPV) was known as a good hole injecting material, an EL device with ITO/PPV/PQx/metal type structure was suggested. It was shown that the quantum efficiency of the cell was higher than that of ITO/PPV/metal cell. Related physical and optical properties of PQx derivatives are also investigated.