Photonic-crystal near-ultraviolet reflectance filters fabricated by nanoreplica molding

One-dimensional photonic-crystal reflectance filters operating in the near-ultraviolet wavelengths were fabricated using nanoreplica molding from a silicon surface structure “master” template, patterned using electron-beam lithography. The fabricated devices produce a narrow linewidth reflectance resonance at a wavelength of 411 nm for TM polarized illumination and a broadband reflectance characteristic between 402 and 439 nm for TE polarized illumination. The measured reflectance spectra are accurately predicted by Rigorous Coupled Wave Analysis computer simulations, which demonstrate the capability for designing similar filter performance for wavelengths ≪350 nm through minor adjustment of the photonic-crystal lattice period.