Method of Manufacturing Structural, Optically Transparent Glass Fiber-Reinforced Polymers (tGFRP) Using Infusion Techniques with Epoxy Resin Systems and E-Glass Fabrics.

Recently, fiber-reinforced, epoxy-based, optically transparent composites were successfully produced using resin transfer molding (RTM) techniques. Generally, the production of structural, optically transparent composites is challenging since it requires the combination of a very smooth mold surface with a sufficient control of resin flow that leads to no visible voids. Furthermore, it requires a minimum deviation of the refractive indices (RIs) of the matrix polymer and the reinforcement fibers.

On the depolarization in granular thin films: a Mueller-matrix approach.

We describe a general method to disclose the information hidden in Mueller matrices experimentally obtained from depolarizing samples. Although spectroscopic Mueller-matrix ellipsometry allows for a model-free characterization of inhomogeneous samples, i.e.

Large-Area Two-Dimensional Plasmonic Meta-Glasses and Meta-Crystals: a Comparative Study.

The geometrical arrangement of metallic nanoparticles plays a crucial role on the optical response of nanoplasmonic samples due to particle-particle interactions. In this work, large-area, two-dimensional meta-glasses (random arrangements) and meta-crystals (periodic arrangements) made of identical metallic nanoparticles are investigated for three different particle densities of 5, 10, and 15 discs/μm. A direct comparison between random and periodically ordered arrays is presented.

Physical interpretation of Mueller matrix spectra: a versatile method applied to gold gratings.

The interaction of nanostructures, periodic or random, with polarized light creates very rich physics where scattering, diffraction and absorbance are linked to a variety of dispersive modes and coupling effects. Each of these excitations depends strongly on polarization, angle of incidence, azimuthal orientation of the sample and wavelength. The entire optical response can be obtained, independently from any model, by measuring the Mueller matrices at various k-vectors over a broad frequency range.

Tuning the dielectric properties of metallic-nanoparticle/elastomer composites by strain.

Tunable metal/dielectric composites are promising candidates for a large number of potential applications in electronics, sensor technologies and optical devices. Here we systematically investigate the dielectric properties of Ag-nanoparticles embedded in the highly flexible elastomer poly-dimethylsiloxane (PDMS). As tuning parameter we use uniaxial and biaxial strain applied to the composite.

Far-infrared spectroscopy on free-standing protein films under defined temperature and hydration control.

The functionality of proteins is governed by their dynamics. We have performed a systematic investigation on four different proteins in the far-infrared spectral region under control of the two external parameters that have the strongest influence on the dynamics, namely temperature and hydration. The absorption measurements covering the frequency range from 40 cm(-1) to 690 cm(-1) (1-20 THz) close the gap between the well-studied mid-infrared and the recent THz investigations.

Periodic nanostructures: spatial dispersion mimics chirality.

Polarization rotation in isotropic materials is commonly associated with chirality, i.e., structures with a handedness which are not identical with their mirror image.

How holes can obscure the view: suppressed transmission through an ultrathin metal film by a subwavelength hole array.

If a metal film, thick enough to be totally opaque, is perforated by tiny subwavelength holes in an orderly fashion, the transmission will be enhanced extraordinarily [T. W. Ebbesen, Nature (London) 391, 667 (1998)].

Characterization of continuous-wave terahertz sources: laser mixing versus backward-wave oscillators.

The tunable, continuous-wave terahertz (THz) radiation generated by mixing of two near-infrared laser lines in an antenna-coupled photomixer is compared with the monochromatic beam of backward-wave oscillators. The electromagnetic radiation of the different THz sources is characterized with respect to intensity, linewidth, degree of linear polarization, angular characteristic, beam quality, and M(2) value. The results are discussed with respect to applications in THz spectroscopy and imaging.

Morphological and electrical characteristics of biofunctionalized layers on carbon nanotubes.

In this study we have investigated the morphology and electrical characteristics of protein layers non-covalently adsorbed onto an irregular network of carbon nanotubes (CNT). The layer system presents a prototype for an ion-sensitive field-effect transistor based on CNT-networks. The complementary characterization techniques AFM and ellipsometry give the overall morphology of the functionalized layer system and in combination with concentration dependent measurements a detailed image of the adsorption dynamics.

LEED, STM, and TDS studies of ordered thin films of the rhombus-shaped polycondensed aromatic hydrocarbon C54H22, on MoS2, GeS, and graphite.

Low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), and thermal desorption spectroscopy (TDS) are used to study vacuum vapor-deposited molecular thin films of the rhombus-shaped polycondensed aromatic hydrocarbon "rhombus-C54", C54H22, on MoS2 and graphite (0001) and on GeS (010) substrates. It is found that this compound forms well-ordered incommensurate superstructures of the closest packed flat-lying molecules in well-defined azimuthal orientations to the substrate. These films are thermally remarkably stable.