Highly efficient refractive index gratings, 35 percent or more, were fabricated by photobleaching into an azo polymer film with a large second-order optical nonlinearity. From IR spectroscopy, it was confirmed that 532 nm laser light cause photobleaching of azo polymer film effectively. As the modulation depth of relief structure observed by AFM was less than 30 nm, the effect of relief structure observed by AFM was less than 30 nm, the effect of relief structure on the diffraction efficiency is negligible. From these results, we confirmed that the grating obtained in this experiment was mainly caused by photobleaching. We observed that coupling efficiency of the grating is dependent on polarization direction of guiding beam. This is considered to related to the anisotropic refractive index change due to the photobleaching in vertical plane of film.
By using the low kinetic energy particle process, Cu films grown on SiO2 under a sufficient amount of energy deposition exhibit almost perfect crystal orientation conversion from Cu(111) to Cu(100) after thermal annealing. This crystal orientation conversion is always accompanied by giant-grain-growth in the film as large as several hundred micrometers. The crystal orientation conversion is primarily governed by the total energy density deposited to the film during film growth. In this work, we have discovered another important factor that governs the crystal orientation conversion, i.e., the total amount of energy deposition to the entire film. The crystal orientation conversion by thermal annealing is observed only for film thickness greater than 1.0 micrometers . In terms of electrical properties, the resistivity of giant- grain-Cu film at a room temperature is 1.78 (mu) (Omega) (DOT)cm, which is almost identical to the bulk resistivity (1.72 (mu) (Omega) (DOT)cm). And electromigration lifetime for giant- grain-Cu interconnect is approximately 3 - 5 orders of magnitude larger than those for Al-alloy interconnects at a room temperature.