Heidt A.M.,Stellenbosch University |
Heidt A.M.,Institute of Photonic Technology
Journal of the Optical Society of America B: Optical Physics | Year: 2010
Supercontinuum (SC) generation in all-normal dispersion photonic crystal fiber under high energy femtosecond pumping is numerically investigated. It is shown that coherent octave spanning SC spectra with flatness of better than ±1 dB can be achieved over the entire bandwidth. A single pulse is maintained in the time domain, which may be externally compressed to the sub-10 fs regime even by simple linear chirp elimination. The single optical cycle limit is approached for full phase compensation, leading to peak power spectral densities of multiple kilowatts/nanometer. The generated SC is therefore ideal for applications which require high broadband spectral power densities as well as a defined pulse profile in the time domain. The properties of the generated SC are shown to be independent of the input pulse duration. © 2010 Optical Society of America.
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ENERGY.2008.10.1.2;NMP-2008-2.6-1 | Award Amount: 4.08M | Year: 2009
Thin film solar cells, based on non-toxic, abundant and air-stable silicon (Si) will probably, based on forecasts, dominate the photovoltaic market in the future and thus replace bulk Si from its leading position. This prognosis is fostered by the strong cost reduction potential due to highly effective materials utilization at low energy consumption. However, thin film Si suffers from inherently small grains, which limits efficiencies to ~10% due to carrier recombination at grain boundaries. A radical innovation of the Si thin film materials synthesis route is needed to circumvent this problem. ROD_SOL aims at the synthesis of Si nano-rods, densely packed at sufficiently large diameters (few 100 nms) and lengths (>1m for sufficient carrier absorption in indirect semiconductors) directly on cheap substrates like glass or flexible metal foils. The idea is to grow Si nano-rods from the gas phase that are inherently defect free, with a wrapped around pn-junction that bares the potential to decouple absorption of light from charge transport by allowing lateral diffusion of minority carriers to the pn-junction, which is at most a few hundred nm away, rather than a few m as in conventional thin film solar cells. That way, efficiencies as in bulk Si are expectable, however, with the advantage that the nano-rod carpet layer, is at most a few m thick. A nano-rod carpet that thin shows a strongly increased optical absorption. Thus, the nano-rod carpet is not only the active solar cell element but at the same time its own light trapping structure. For synthesis of the nano-rods, development of suitable contact materials and characterization of physical and structural properties four experienced research institutes have joined forces. Despite the fundamental materials research to be in focus, three companies joined the consortium to directly test and implement the novel materials and processes in a well proven, industrially viable thin film solar cell concept.
Agency: European Commission | Branch: FP7 | Program: CP | Phase: SPA.2010.2.2-01 | Award Amount: 2.58M | Year: 2011
Recently, research in astrophysics has yielded amazing new insight in the origin, evolution and structure of the Universe, and fundamental processes governing this highly dynamical system. Most of this progress was achieved thanks to the availability of extremely sensitive detectors. Common features for such detectors are extremely low noise and very small background, and the main solutions for achieving this are based on extremely low operating temperature allowing measurement of signal in superconducting phase. Space-based applications using superconducting technology, however, are rare and considerable effort is being put in their development. In this critical field, European technology has recently fallen notably behind the state of the art defined by the USA. We will use Transition Edge Sensor (TES), Microwave Kinetic Inductance Detector (MKID), and Metallic Magnetic Calorimeter (MMC) detector arrays and develop readout systems using multiplexed Superconducting Quantum Interference Device (SQUID) amplifiers for focal plane sensor arrays in the X-rays, optical and far infrared wavelengths. The above detector concept has potential for use in a wide range of space missions, and it has also applications in other fields of research outside astronomy, where weak photon signals are measured with high accuracy. The main aim of this project is to improve the European technology readiness level (TRL) and brigde the gap to the global state-of-the-art and advance European independence in the above key technology. The partners of this collaborative project are the key developers of SQUID technology in Europe (VTT Finland, IPHT Germany), and represent the highest international level of scientific expertise in astrophysics research and instrument development (SRON Netherlands, University of Leicester United Kingdom, Max-Planck Institute for Radio Astronomy Germany, and University of Helsinki Finland). Also two SME partners are involved in minor supporting work packages.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP-2009-1.2-1 | Award Amount: 5.15M | Year: 2011
The NanoPV project aims at making a breakthrough step-change in photovoltaics by the removal of a set of bottlenecks which have been identified to block the application of nanostructures for high-efficiency, low-cost solar cells. The bottlenecks arise from the present lack of up-scalable processes that can meet the needs for nanomaterials in PV applications, and the lack of relevant equipment and industrial lines. In order to remove these bottlenecks, the main objectives of NanoPV are: 1) To develop technologies that can increase the efficiency and reduce the processing cost of existing silicon solar cell technologies using nano-scale effects provided by nanomaterials to above 20% for wafer based and above 15 % for thin film silicon based solar cells at a processing cost for modules well below 1 /watt. 2) To design and to fabricate low cost solar cells entirely from nanomaterials by using nanostructures. An efficiency of above 10 % at processing costs well below 1 /watt is targeted with potential of further significant improvements in the future. 3) To develop up-scalable cost effective processes and equipment in order to implement both enhanced standard solar cells and solar cell based on nanomaterials as well as related modules to existing pilot lines. 4) To create new market opportunities for the industrial partners. Nanotechnology will be applied for both already existing conventional Si solar cells (wafer and thin-film based) and for advanced solar cells entirely based on nanostructures. The main scientific efforts will be on understanding and exploitation of such nanomaterials as i) 0D quantum dots, nanocrystals and nanoparticles, ii) 1D nanowires and nanorods, and iii) 2D nanomaterials such as ultrathin layers. A large number of specialised technologies will be applied in the project. Therefore, in order to ensure successful completion, a comparatively large consortium of 9 complementary research partners and 3 industries has been assembled.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP-2007-1.1-1 | Award Amount: 4.94M | Year: 2008
The cause of diseases is often unknown, but their origin can frequently be found at the biomolecular and cellular level situated on nm-scale. Early diagnostics combined with early intervention on that nanoscale is one of the holy grail of modern medicine. Inorganic nanoparticles are very promising agents in that respect. One of the promising biomedical applications of these nanoparticles is their use as agents for tumor hyperthermia. Hyperthermia is a form of cancer treatment that uses an elevated temperature to kill the tumor tissue. Compared to the more conventional surgical procedures, it is hailed as a less invasive approach that could be used for small, non-defined tumors. Well-designed instrumentation in combination with engineered inorganic nanoparticles that (a) possess the desired physical properties to generate a local heat and that (b) can specifically target the tumor offer immense potentials for targeted hyperthermia therapy. The overall objective of the present multi-disciplinary project is to develop and to explore various metal/magnetic nanoparticles as agents for targeted tumor therapy. To strive for this overall objective, a successful integration and convergence of different technologies at the nanoscale is indispensable. In this project, we will focus on the synthesis routes of tailor designed biofunctionalized nanoparticles for hyperthermia. This requires a profound physical and chemical characterization of the synthesized nanostructures, but the project is certainly not limited hereto. It will also include a toxicological and biological evaluation of the different nanoparticles. Hereby a detailed exploration and characterization of the interaction mechanism of the biological entities and the nanostructures will be pursued to obtain a better understanding of the phenomena occurring at the nanoscale. In addition, this project also comprises the design of advanced instrumentation that can be used for a controlled hyperthermia treatment.
Agency: European Commission | Branch: FP7 | Program: BSG-SME | Phase: SME-2012-1 | Award Amount: 1.48M | Year: 2013
Chemotherapy is the standard care for the treatment of non-small cell lung carcinoma (NSCLC) patients, however most of non-small cell lung cancer tumours are not sensitive to this treatment. As an alternative to chemoterapy, target therapy with gefitinib (epidermal growth factor receptor-tyrosine kinase inhibitor) has been used in clinical practice in patients with tumours harbouring mutations in EGFR gene, improving their treatment effectiveness. For that reason EGFR mutations analysis should be perform to support the treatment decision for a patient with NSCLC. Despite all the foreseen benefits of EGFR genotyping, the current PCR-based methods used have been shown some associated bottlenecks: i) use of complex samples (tumour biopsy embedded in Formalin Fixed Paraffin, FFPE), ii) require a better understanding from the clinical geneticist to accurately interpret the information provided and to setup the best line of therapy and treatment and iii) the assays are quite expensive and time-consuming. New age diagnostic tools, such as microfluidic platforms and nanodiagnostics are emerging technologies for DNA analysis requiring lower sample volumes and providing comparable sensitivity and specificity at lower costs. Nonetheless, sample preparation and detection of the result of a chemical analysis on-chip are still weak points in many lab-on-a-chip devices. The current proposal, aiming the integration of all laboratory-based process steps in one single step, is both challenging and feasible: development of a microfluidic chip that combines blood sample processing (DNA extraction/purification, multiplex amplification) and detection of EGFR mutations in tumour DNA by means of gold and silver-nanoparticles (Ag and Au-nanoprobes). Furthermore a microfluidic chip analyser with an integrated user-friendly software to report genotyping results will be developed.
Wicker K.,Friedrich - Schiller University of Jena |
Wicker K.,Institute of Photonic Technology
Optics Express | Year: 2013
The artefact-free reconstruction of structured illumination microscopy images requires precise knowledge of the pattern phases in the raw images. If this parameter cannot be controlled precisely enough in an experimental setup, the phases have to be determined a posteriori from the acquired data. While an iterative optimisation based on cross-correlations between individual Fourier images yields accurate results, it is rather timeconsuming. Here I present a fast non-iterative technique which determines each pattern phase from an auto-correlation of the respective Fourier image. In addition to improving the speed of the reconstruction, simulations show that this method is also more robust, yielding errors of typically less than ? /500 under realistic signal-to-noise levels. © 2013 Optical Society of America.
Aviles-Espinosa R.,Institute of Photonic Technology
Journal of biomedical optics | Year: 2010
Live microscopy techniques (i.e., differential interference contrast, confocal microscopy, etc.) have enabled the understanding of the mechanisms involved in cells and tissue formation. In long-term studies, special care must be taken in order to avoid sample damage, restricting the applicability of the different microscopy techniques. We demonstrate the potential of using third-harmonic generation (THG) microscopy for morphogenesis/embryogenesis studies in living Caenorhabditis elegans (C. elegans). Moreover, we show that the THG signal is obtained in all the embryo development stages, showing different tissue/structure information. For this research, we employ a 1550-nm femtosecond fiber laser and demonstrate that the expected water absorption at this wavelength does not severely compromise sample viability. Additionally, this has the important advantage that the THG signal is emitted at visible wavelengths (516 nm). Therefore, standard collection optics and detectors operating near maximum efficiency enable an optimal signal reconstruction. All this, to the best of our knowledge, demonstrates for the first time the noninvasiveness and strong potential of this particular wavelength to be used for high-resolution four-dimensional imaging of embryogenesis using unstained C. elegans in vivo samples.
Dutz S.,Institute of Photonic Technology |
Hergt R.,Institute of Photonic Technology
International Journal of Hyperthermia | Year: 2013
In this review article we present basic principles of magnetically induced heat generation of magnetic nanoparticles for application in magnetic particle hyperthermia. After explanation of heating mechanisms, the role of particle-particle as well as particle-tissue interactions is discussed with respect to achievable heating power of the particles inside the tumour. On the basis of heat transfer theory at the micro-scale, the balance between generated and dissipated heat inside the tumour and the resulting damaging effects for biological tissue is examined. The heating behaviour as a function of tumour size is examined in combination with feasible field strength and frequency. Numerical calculations and experimental investigations are used to show the lower tumour size limit for tumour heating to therapeutically suitable temperatures. In summary, this article illuminates practical aspects, limitations, and the state of the art for the application of magnetic heating in magnetic particle hyperthermia as thermal treatment of small tumours. © 2013 Informa UK Ltd.
Agency: European Commission | Branch: FP7 | Program: MC-IIF | Phase: FP7-PEOPLE-2013-IIF | Award Amount: 168.79K | Year: 2015
This project aims to reinforce the research excellence of the German Institute of Photonic Technology through knowledge sharing with incoming top-class Australian researcher Dr Stephen Warren-Smith to work in Europe on research in the vibrant field of proteomic sensing. Proteomics, the study of proteins and their function, is a powerful technique that can be used as a diagnostic tool for various human diseases. Currently, samples must either be extracted from easily accessible fluids such as blood or from invasive biopsy samples. There is an urgent need for techniques that can perform measurements on samples that are difficult to access, such as uterine fluid, without invasive surgery. We propose to develop highly sensitive micro-interferometers and micro-resonators integrated in optical fibres as miniaturized sensing elements for protein detection in medical applications. This will be achieved by combining sensitive resonance effects, such as a Fabry-Perot interferometer, in conjunction with specific antibodies. Such sensors have already proven successful in physical sensing, such as temperature and strain, and are now in prime position to be extended to the application of biomedical diagnostics. This project will advance these sensors by theoretically and experimentally investigating multi-channel sensors for the purpose of multiplexing biomarkers. This is a critical step for biosensing as it is rare that measuring a single biomarker, without controls, can provide a definitive diagnosis. To demonstrate a specific application the detection of proteomic endometrial biomarkers in difficult to access uterine fluid will be targeted. This project aims to reach a level of maturity where the biomarkers can be tested in a clinical trial in a subsequent project. This will provide an opportunity for continued engagement between Australia and Germany to address this significant challenge.