In this paper we propose a structure to compensate the propagation loss of surface plasmons by using multiple quantum wells as a gain medium. We analyze the required gain for lossless surface plasmon propagation for different thicknesses and widths of the metallic guiding layer. We study the effects of the gain layers and a finite height superstrate on the surface plasmon mode and its propagati...

InAs-based heterostructure barrier varactor (HBV) diodes with In0.3Al0.7As0.4Sb0.6 as the barrier material are demonstrated. Current–voltage and capacitance–voltage characteristics, as well as S-parameters, of HBV diodes with varying barrier thicknesses are examined. Maximum capacitance values and maximum-to-minimum capacitance ratios greater than those predicted by traditional HBV models were ...

Optical data are essential for the accurate nondestructive determination of profiles of periodic structures in integrated-circuit technology. In rigorous coupled-wave analysis, the sample is generally modeled as layers consisting of a single material and the ambient. We extend present capabilities to the analysis of structures with overlayers and demonstrate our approach by determining quantita...

We present a novel method for the ejection of sedimenting microparticle solutions by a non-contact drop-on-demand dispensing system with integrated mixing technology. The system enables the generation of single liquid droplets in the nanoliter range containing similar amounts of solids. The system is evaluated for a process time of more than 4 h and is applied to produce particle layers with ho...

We present an algorithm for optimizing optical structures based on Markov Decision Processes. Our method is successfully demonstrated on a one-dimensional stack of dielectric slabs, where we wish to choose a combination of slab thicknesses and refractive indices to approximate a target reflection spectrum. We show that this algorithm is less susceptible to being caught in local minimum and has ...

Microfluidic devices were fabricated using multilayer softlithography1. Photolithography masks were designed using Clewin (WieWeb) and written directly on AZ precoated chromium substrates using a Heidelberg DWL200 laser writer. Molds were fabricated on 4” silicon wafers using a Karl Suss MA6 mask aligner. Two photoresists were used to generate either square (SU8) or round (AZ) channel profiles....

It is shown that experimentally obtained isotherms of adsorption on solid substrates may be completely reconciled with Lifshitz theory when thermal fluctuations of the free film surface are taken into account. This is demonstrated for hydrogen adsorbed on gold as a model system. Analysis of the fluctuation contributions allows one to determine the surface tension of the free hydrogen film as a ...

So close, but yet so far: G. sulfurreducens c-type cytochromes become reduced as biofilms grow on electrodes beyond a few cell thicknesses, even if the electrode is poised well above the potential required to oxidize all cytochromes. Cytochrome redox state also lags behind rapid potential changes during voltammetry, but only when the films are multiple cell layers thick, as would be expected if...

The carrier tunneling dynamics of self-assembled InAs quantum dots (QD) is studied using time-resolved conductance measurements of a nearby two-dimensional electron gas (2DEG). The coupling strength (tunneling time) between the QDs and the 2DEG is adjusted by different thicknesses of the spacer layers. We demonstrate a strong influence of charged QDs on the conductance on the 2DEG, even for ver...