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This paper describes performance characteristics of a bridge‐connected magnetic circuit with single output winding in dc control. The difference between positive and negative amplitudes of output current changes with the dc control current. An application of the bridge‐connected magnetic circuit to a dc current detector is presented in this paper.

In this paper, we study the efficiency of several types of all-dielectric, non-resonant, antireflection, and light-trapping coatings for the enhancement of photovoltaic absorption in thin-film silicon solar cells. We compare the enhancement of the photovoltaic absorption offered by a square array of nano-pillar shaped voids in the dielectric covering of the cell with that granted by a flat blooming layer, and a densely packed array of dielectric nanospheres. We optimize these coatings and show that the newly proposed nanostructure allows a significant increase of the photovoltaic absorption. The dependence of antireflection and light-trapping properties on the angle of incidence is numerically investigated, and it is shown that the array of voids keeps optimal also after averaging over the incidence angles.

We have recently proposed a solid state heat pump based on photon mediated heat transfer between two large-area light emitting diodes coupled by the electromagnetic field and enclosed in a semiconductor structure with a nearly homogeneous refractive index. Ideally the thermophotonic heat pump (THP) allows heat transfer at Carnot efficiency but in reality there are several factors that limit the efficiency. The efficient operation of the THP is based on the following construction factors and operational characteristics: (1) broad area semiconductor diodes to enable operation at optimal carrier density and high efficiency, (2) recycling of the energy of the emitted photons, (3) elimination of photon extraction losses by integrating the emitting and the absorbing diodes within a single semiconductor structure, and (4) eliminating the reverse thermal conduction by a nanometer scale vacuum layer between the diodes. In this paper we develop a theoretical model for the THP and study the fundamental physical limitations and potential of the concept. The results show that even when the most important losses of the THPs are accounted for, the THP has potential to outperform the thermoelectric coolers especially for heat transfer across large temperature differences and possibly even to compete with conventional small scale compressor based heat pumps.

Graphene nanomeshes (GNMs) are expected to be a high-performance channel material for metal-oxide-semiconductor field-effect-transistors (MOSFETs), since they can open up a band gap in a large sheet of graphene thin film by simply introducing two-dimensional periodical nanoscale holes. In this paper, we theoretically investigate the electronic band structures and the electron transport properties of GNMs based on a tight-binding approach. We demonstrate that GNMs have the capability of band structure engineering by controlling its neck width and furthermore the potential ability providing high current drivability when applied to a field-effect-transistor channel.

Two-photon-induced photopolymerization (2PP) has gained increased interest due to the capability of manufacturing three-dimensional structures with very high feature resolution. To assess the suitability of photopolymer systems for 2PP, methods have to be developed that allow a screening of the efficiency of monomer-initiator combinations in the context of high throughput, large processing window and geometric quality of the final parts. In this paper, a method for evaluating 2PP structures is described. For this purpose, the double-bond conversion of fabricated 2PP structures was measured giving quantifiable results about the efficiency of the photoinitiator. The method is based on local measurement of the double-bond conversion of the photopolymer using a microscope in combination with infrared spectroscopy. The obtained double-bond conversion is a measure for the efficiency of the photopolymer system (initiator in combination with monomer), and thus allows to compare different photopolymers in a quantitative way. Beside this evaluation of 2PP structures, fabrication of complex 3D structures was done to determine the limits of the 2PP technology for miscellaneous components.

Linear motors find their utilization in an increasing number of industrial applications. Permanent magnet linear synchronous motors (PMLSMs) are favorable in many applications due to their servo characteristics, robustness, and high force density. The major disadvantage of moving coil type PMLSMs is the cable slab that energizes the coils from the fixed world to the moving parts of the machine. These cable slabs introduce extra wear and dynamical distortions. Moreover, in precision application the cable slab is supported by additional linear drives. These disadvantages can be eliminated if the coils could be powered wirelessly. In this paper two topologies are proposed that are capable of transferring 1 kW of power at most. The transformer part of the CET is characterized by means of two dimensional finite element analysis, and the influence of using additional capacitors to boost the output power is examined. Furthermore, an analysis of the core losses is conducted. Conclusions are drawn from the results.

This paper demonstrates that the spatial distribution of electronic states of an arsenic ion implanted Si (111) substrate can be observed by using a wavelength tunable second harmonic (SH) microscope in a wide photon energy range from 2hω=1.96 to 5.19 eV. The contrast in the SH intensity images between the As-doped area and the nondoped area depends greatly on the SH photon energy. For 2hω>3 eV, optical second harmonic generation (SHG) from the nondoped area was stronger than from the doped area, and the contrast was reversed for 2hω