Fingerprint enhancement often includes either physical or chemical approaches, such as fingerprint powder or cyanoacrylate fuming, to improve the quality of a fingerprint for visualization and analysis. However, these methods become more complex when fingerprints are partial bloody, and these procedures may interfere with downstream DNA analysis. Columnar thin film (CTF) deposition is a type of nanotechnology that utilizes an evaporant material to enhance a fingerprint under low-pressure conditions.
View Article and Find Full Text PDFAs subwavelength nanostructures are receiving increasing attention for photonic and plasmonic applications, we grew nanostructured porous silicon (n-PS) and hybrid n-PS/Ag layers onto silicon substrates and measured their reflection and absorption characteristics as functions of the wavelength, angle of incidence, and polarization state of incident light. The experimental results show that the absorption characteristics of the hybrid n-PS/Ag layer can be controlled by selecting the appropriate combination of its thickness and porosity, together with the density of infiltrant silver nanoparticles. The observed wideband optical absorption characteristics of the hybrid n-PS/Ag layers might be useful in light-harvesting devices and photodetectors, since the overall efficiency will be increased as a result of increased field-of-view for both s- and p-polarization states of incident light.
View Article and Find Full Text PDFTheory shows that a slab of a dielectric structurally chiral material (DSCM) exhibits both linear and circular dichroisms because of its anisotropy and structural chirality, for normal as well as oblique incidence. This conclusion was confirmed by fabricating a chiral sculptured thin film and measuring the spectra of its reflectances and transmittances, both linear and circular. Signatures of the circular Bragg phenomenon are evident in the spectra of all reflectances, transmittances, absorptances, and dichroisms.
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