Highly nonlinear optic nucleic acid thin-solid film to generate short pulse laser.

Using aqueous precursors, we report successfully fabricating thin-solid films of two nucleic acids, ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). We investigated the potential of these films deposited on a fiber optic platform as all-fiber integrated saturable absorbers (SAs) for ultrafast nonlinear optics. RNA-SA performances were comparable to those of DNA-SA in terms of its nonlinear transmission, modulation depth, and saturation intensity.

Fast numerical Fourier analysis of moiré pattern induced by a periodic metallic array on top of the microscopically patterned red-green-blue light sources.

An accurate and fast moiré pattern analysis algorithm is proposed for a periodic metallic array placed adjacent to a patterned red-green-blue (RGB) light source with a microscopic gap utilizing Fourier transform along with the human eye contrast sensitivity function. We analyzed how the moiré pattern evolved varying tilt angles and metal array periodicities placed on the top of RGB light sources, which have their own spatial periodicities. Based on multiplicative model, moiré patterns were numerically generated and the influences of 70 tilt angles and 60 periodicities on the moiré standard deviation were thoroughly analyzed to minimize moiré visibility.

Strong polarization dependence in the optical transmission through a bull's eye with an elliptical sub-wavelength aperture.

Strong polarization dependence in the optical transmission through a bull's eye with a central elliptical aperture in a thin Au film is analyzed numerically by finite difference time domain (FDTD) method. Focusing on the impacts of the structural anisotropy, detailed investigation of polarization dependent enhanced optical transmission (EOT) of light is discussed in terms of the resonance intensity variations caused by the incident light polarization and the geometrical parameters of bull's eye. We found that the light polarized along the minor axis of the elliptic aperture has significantly larger EOT by more than three orders of magnitude than the other orthogonal polarization, which can be further utilized in polarized EOT devices.

Enhanced optical transmission through sub-wavelength centered-polygonal hole arrays in silver thin film on silica substrate.

We numerically investigated the enhanced optical transmission through sub-wavelength centered-polygonal hole arrays (CPHA) in a thin Ag film deposited on the silica substrate. In octagonal and decagonal-CPHAs, we observed new hybrid transmission characteristics that were inherited from both crystalline and quasi-crystalline hole arrays. This peculiar nature was attributed to the unique arrangement of CPHAs which can be covered with copies of a single unit cell as in crystalline arrays, and their rotational symmetry as observed in quasi-crystalline arrays.

Plasmonically enhanced optical transmission through a metalized nanostructured photonic crystal fiber taper.

A subwavelength holey plasmonic structure was proposed by adiabatically tapering a photonic crystal fiber (PCF) and subsequently metalizing the cleaved end facet. By coupling a white light into the PCF side, we experimentally observed an enhanced optical transmission in the spectral domain through the plasmonic structure at the tapered end. We further showed numerically that the proposed device renders a focused directional beam, due to its Fresnel-zone-like configuration and the plasmonic lensing effects.