A simple methodfor the fabrication of anodic aluminum oxide films (AOFs) with perfectly ordered structures (see Figure) is presented by these authors. A common optical grating is used to prepattern the aluminum substrate, which is subsequently anodized under mild conditions to yield an AOF with a photonic bandgap in the visible region.

We investigate the blue photoluminescence of Si+-implanted SiO2 films under picosecond UV excitation. The emission intensity exhibits a nonlinear increase with increasing excitation intensities, accompanied by pulse shortening. The photoluminescence decays nonmonoexponentially in time. However, the nonlinearities are not associated with significant spectral narrowing. To explain the results, we propose and numerically investigate a kinetic model based on competition between radiative (both spontaneous and stimulated) and nonradiative recombination in isolated luminescence centers in the SiO2 matrix. Good agreement between theoretical and experimental data seems to confirm the existence of stimulated emission in the films, however, under extremely high excitation densities only (approximately 100 MW/cm2).

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The optical properties of two-dimensional photonic crystals (PhCs) in anodic aluminum oxide (AAO) films obtained using a simple and low-cost pre-patterning procedure are described. The prepatterning of the initial Al film surface was carried out by imprinting with an optical diffraction grating; the anodization of the prepatterned sample led to the formation of a good quality, large-area PhC with a triangular lattice of air holes (lattice period a ¼ 0:48 mm, hole radius r ¼ 0:2 mm) in an AAO film. The optical transmission spectra of the sample were measured at visible wavelengths in the range of 0.4-1.0 mm for various incidence angles and linear polarizations of the probing light. The detailed analysis of the transmission data indicates a photonic band gap in the 0.9-1.0 mm wavelength range for light waves linearly polarized in the direction perpendicular to the axes of PhC pores.

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