Integrated photonic devices have traditionally been designed for data communications using exclusively solid-state materials. However, a vast area of potential applications, in particular in the life sciences, involve interactions of light with liquids and gases. Recently, a number of optofluidic approaches have been considered that are aimed at integrating such non-solid media with chip-scale photonic structures. We have developed a versatile, planar photonic platform based on hollow-core optical waveguides (ARROWs).

Wind turbines are often deployed in arrays of hundreds of units, where wake interactions can lead to drastic losses in power output. Remarkably, while the theoretical “Betz” maximum has long been established for the output of a single turbine, no corresponding theory appears to exist for a generic, large-scale energy extraction system. We develop a model for an array of energy-extracting devices of arbitrary design and layout, first focusing on the fully-developed regime, which is relevant for large wind farms.

Many organic and hybrid thin film electronic devices (e.g. memory diodes, solar cells, light emitting diodes, transistors, capacitors) typically contain a functional layer based on a blend comprising multiple polymeric or small-molecular species whose properties cooperatively give rise to a specific function. Depending on the desired functionality, phase separation during film processing is either encouraged or suppressed. As usually at least one blend component is polymeric, mutual segmental repulsion readily overcomes the entropic driving force to form stable mixtures.

The aggregation of p-conjugated materials significantly impacts on the photophysics, and thus on the performance of optoelectronic devices. Nevertheless, we know comparatively little about the laws governing aggregate formation of p-conjugated materials from solution. In this talk, I shall compare, discuss and summarize how aggregates form for three different types of compounds, that is, homopolymers, donor-acceptor type polymers and low molecular weight compounds.

The Center for Nanoinetgration Duisburg-Essen (CENIDE) is a research center that focuses on nanoscience as the main research area of the University of Duisburg-Essen (UDE, Germany). Since 2005, CENIDE links the activities in natural science, engineering and medicine at the UDE that deal with the nano dimension.

Integrating high-performance III-V devices on the mature silicon platform has been a long pursuit over the past few decades. Direct epitaxial growth offers an alternative technology to bonding.  Using nano-patterned Si substrates, we created III-V on silicon templates with low defect density and smooth surface morphology for laser growth.  Such antiphase-domain (APD)-free III-V on silicon compliant templates with high crystalline quality (benchmarked by narrow XRD halfwidths) are grown without the need of special off-cut substrates and/or Ge buffer.

Mobile computing is experiencing a technological renaissance, and the Web is Florence. Throughout the past decade, the Web has redefined the way people retrieve information, communicate with one another, and extract insights. Although rife with opportunity, the energy-constrained nature of mobile devices is a major roadblock to the potential that next-generation Web technologies promise.

In this talk we'll present the latest results on the integration of silicon-photonic interconnects into a monolithic platform (45nm SOI logic process and bulk CMOS memory periphery process). These include world's first microprocessor communicating to the outside world with monolithically integrated Si-Photonic devices, as well as the first demonstration of photonics in a bulk CMOS process.

The production and use of engineered nanoparticles (ENP) inevitably leads to their release into aquatic environments. Concerns therefore arise over the possibility that ENPs might pose a threat to consumers and the environment. Investigations on the vulnerability of natural systems to ENPs are hampered by the absence of suitable analytical methods that are capable of detecting and quantifying ENPs in complex aqueous matrices. Analytical data concerning the presence of ENPs is therefore scarce.

I will discuss two main themes of research in my group addressing nano-photonics on silicon.  I will discuss recent advances on nanopillar devices based on III-V compound directly grown on silicon.