Structural properties of ultrathin SrO film deposited on SrTiO.

The role of epitaxial strain and chemical termination in selected interfaces of perovskite oxide heterostructures is under intensive investigation because of emerging novel electronic properties. SrTiO (STO) is one of the most used substrates for these compounds, and along its direction allows for two nonpolar chemical terminations: TiO and SrO. In this paper, we investigate the surface morphology and crystal structure of SrO epitaxial ultrathin films: from 1 to about 25 layers grown onto TiO -terminated STO substrates.

A comparative study of defect formation in GaAs nanocrystals selectively grown on nanopatterned and flat Si(001) substrates.

Crystal defects present in GaAs nanocrystals ∼15-50 nm in diameter and grown by metal organic vapor phase epitaxy on top of two different nanopatterned Si(001) substrates (nanopillars and nanotips with ∼40-80 nm openings embedded in a SiO matrix) and on a planar substrate, have been investigated by means of atomic-resolution aberration-corrected scanning transmission electron microscopy. Conditions of their formation are discussed. The defect analysis of the three GaAs/Si systems reveals a higher defect density in the GaAs crystals grown on nanopillars as compared to those grown on nanotips and the planar substrate, possibly concomitant to the atomic-scale irregularities identified at the patterned Si(001) nanopillars.

POF-yarn weaves: controlling the light out-coupling of wearable phototherapy devices.

Neonatal jaundice (hyperbilirubinaemia) is common in neonates and, often, intensive blue-light phototherapy is required to prevent long-term effects. A photonic textile can overcome three major incubator-related concerns: Insulation of the neonate, human contact, and usage restraints. This paper describes the development of a homogeneous luminous textile from polymer optical fibres to use as a wearable, long-term phototherapy device.

Body-monitoring with photonic textiles: a reflective heartbeat sensor based on polymer optical fibres.

Knowledge of an individual's skin condition is important for pressure ulcer prevention. Detecting early changes in skin through perfusion, oxygen saturation values, and pressure on tissue and subsequent therapeutic intervention could increase patients' quality of life drastically. However, most existing sensing options create additional risk of ulcer development due to further pressure on and chafing of the skin.

Body-monitoring and health supervision by means of optical fiber-based sensing systems in medical textiles.

Long-term monitoring with optical fibers has moved into the focus of attention due to the applicability for medical measurements. Within this Review, setups of flexible, unobtrusive body-monitoring systems based on optical fibers and the respective measured vital parameters are in focus. Optical principles are discussed as well as the interaction of light with tissue.

Resonance light scattering in dye-aggregates forming in dewetting droplets.

Small organic semiconducting molecules assembling into supramolecular J- and H- aggregates have attracted much attention due to outstanding optoelectronic properties. However, their easy and reproducible fabrication is not yet sufficiently developed for industrial applications, except for silver halide photography. Here we present a method based on aggregate precipitation during the phase separation and dewetting of the evaporating dye precursor solution.

Development of a luminous textile for reflective pulse oximetry measurements.

In this paper, a textile-based sensing principle for long term photopletysmography (PPG) monitoring is presented. Optical fibers were embroidered into textiles such that out-coupling and in-coupling of light was possible. The "light-in light-out" properties of the textile enabled the spectroscopic characterization of human tissue.

An optical fibre-based sensor for respiratory monitoring.

In this paper, a textile-based respiratory sensing system is presented. Highly flexible polymeric optical fibres (POFs) that react to applied pressure were integrated into a carrier fabric to form a wearable sensing system. After the evaluation of different optical fibres, different setups were compared.

Characterization of flexible copolymer optical fibers for force sensing applications.

In this paper, different polymer optical fibres for applications in force sensing systems in textile fabrics are reported. The proposed method is based on the deflection of the light in fibre waveguides. Applying a force on the fibre changes the geometry and affects the wave guiding properties and hence induces light loss in the optical fibre.

Helium focused ion beam fabricated plasmonic antennas with sub-5 nm gaps.

We demonstrate a reliable fabrication method to produce plasmonic dipole nanoantennas with gap values in the range of 3.5-20 nm. The method combines electron beam lithography to create gold nanorods and helium focused ion beam milling to cut the gaps.

Growth and alignment of thin film organic single crystals from dewetting patterns.

Studying and understanding the conditions under which organic semiconductors can be engineered to form aligned single crystals in thin films is of primary importance owing to their unique orientation-dependent optoelectronic properties. Efforts to reach this goal by self-assembly from solution-processed films have been rewarded only with limited success. In this article we present a new method to grow single crystalline thin films via solvent annealing.

Fully Metal-Coated Scanning Near-Field Optical Microscopy Probes with Spiral Corrugations for Superfocusing under Arbitrarily Oriented Linearly Polarised Excitation.

We study the effect of a spiral corrugation on the outer surface of a fully metal-coated scanning near-field optical microscopy (SNOM) probe using the finite element method. The introduction of a novel form of asymmetry, devoid of any preferential spatial direction and covering the whole angular range of the originally axisymmetric tip, allows attaining strong field localization for a linearly polarised mode with arbitrary orientation. Compared to previously proposed asymmetric structures which require linearly polarised excitation properly oriented with respect to the asymmetry, such a configuration enables significant simplification in mode injection.

Efficient coupling into and out of high-Q resonators.

The temporal-coupled-mode theory is directly applied to the design of devices that feature a resonator with a high quality factor. For the temporal-coupled-mode theory we calculate the decay rate of the resonator to determine the transmission properties of the device. The analysis using the decay rates requires little computational effort, and therefore the optimum device properties can be determined quickly.

Arrays of anamorphic phase-matched Fresnel elements for diode-to-fiber coupling.

A method for designing microlens arrays that inherently takes into account application requirements and fabrication constraints is presented. Elements with numerical apertures of up to 0.5 have been designed and fabricated by laser beam writing in photoresist and replication in plastic material.