We demonstrate high-pass optical filters with cutoffs in the 0.3-10-micron spectral region. These filters consist of uniform arrays of hollow metallic waveguides, obtained by coating wafers of the previously developed channel-glass (CG) materials with a thin metal film. In these filters the channel diameter controls the cutoff frequency, the channel length controls the sharpness of the cutoff, and the channel density determines the transmission efficiency at cutoff. All of these parameters can be controlled in the CG starting material. The properties of the metal coatings that influence the filter properties are also discussed. Cutoff wavelengths near 300 nm have been achieved to date by using CG materials with submicrometer channel diameters. At all channel diameters, the transmission spectra include a peak just above the cutoff wavelength, where the transmission value can exceed that expected on the basis of the geometrical open area of the CG structure.

Summary form only given. Photonic crystals are nanostructured materials that possess a periodic modulation of the dielectric constant. We have fabricated two-dimensional (2D) triangular photonic crystals in which one of the elements is a phthalocyanine (Pc) dye. These Pc's have a wavelength dependent absorption and large nonlinear absorption and nonlinear refraction coefficients. Thus, in our new photonic crystal materials, there is a wavelength and fluence dependent modulation in both the real and imaginary part of the dielectric constant. We investigate the optical properties of such photonic crystal materials and their potential for optical limiting applications.

Two-dimensional photonic band-structure effects have been observed in the visible and near-uv regions, between 350 and 800 nm. These effects appear in all-solid-state arrays of glass cylinders in a glass matrix. The arrays have center-to-center nearest-neighbor separations between 0.188 and 0.278 μm, perfect long-range order, and low refractive index contrast. For light propagating perpendicular to the cylinder axes, very narrow attenuations appear in the transmission spectra as a result of the photonic band structure. The positions of these attenuations are determined by the periodicity, composition, and symmetry of the arrays.