Microstructured KY(WO4)2:Gd3+, Lu3+, Yb3+ channel waveguide laser

Epitaxially grown, 2.4-μm-thin layers of KY(WO4)2:Gd3+, Lu3+, Yb3+, which exhibit a high refractive index contrast with respect to the undoped KY(WO4)2 substrate, have been microstructured by Ar beam milling, providing 1.4-μm-deep ridge channel waveguides of 2 to 7 μm width, and overgrown by an undoped KY(WO4)2 layer. Channel waveguide laser operation was achieved with a launched pump power threshold of only 5 mW, a slope efficiency of 62% versus launched pump power, and 76 mW output power

Nd-complex-doped polymer channel waveguide laser

Laser operation at 1060 nm with slope efficiency of 0.95% and 440 μW output power for 2% outcoupling was demonstrated in Nd-complex-doped FDA/epoxy channel waveguides, in what to our knowledge is the first report of a rare-earth-ion-doped polymer waveguide laser. The threshold was 45 mW of absorbed pump power

Optically pumped planar waveguide lasers, part I: fundamentals and fabrication techniques

The tremendous interest in the field of waveguide lasers in the past two decades is largely attributed to the geometry of the gain medium, which provides the possibility to store optical energy on a very small dimension in the form of an optical mode. This allows for realization of sources with enhanced optical gain, low lasing threshold, and small footprint and opens up exciting possibilities in the area of integrated optics by facilitating their on-chip integration with different functionalities and highly compact photonic circuits. Moreover, this geometrical concept is compatible with high-power diode pumping schemes as it provides exceptional thermal management, minimizing the impact of thermal loading on laser performance. The proliferation of techniques for fabrication and processing capable of producing high optical quality waveguides has greatly contributed to the growth of waveguide lasers from a topic of fundamental research to an area that encompasses a variety of practical applications. In this first part of the review on optically pumped waveguide lasers the properties that distinguish these sources from other classes of lasers will be discussed. Furthermore, the current state-of-the art in terms of fabrication tools used for producing waveguide lasers is reviewed from the aspects of the processes and the materials involved

Continuous-wave Lasers in Polymer waveguides

Channel waveguides based on a polymer, 6-fluorinated-dianhydride/epoxy, which is actively doped with a rare-earth-ion-doped complex, Nd(thenoyltrifluoroacetone)3 1,10-phenanthroline, have been fabricated. Photoluminescence peaks at 880 nm, 1060 nm, and 1330 nm have been experimentally observed. By optimization of the fabrication\ud procedure of both, host material and optical structure, continuous-wave laser operation on both, the four-level and quasi-three-level transitions near 1060 nm and 880 nm, respectively, has been demonstrated in channel waveguides

‘AU-ICC-Malawi’ conflict: An analysis of Malawi’s position and its implications

No Abstrac

High performance graph analysis on parallel architectures

PhD ThesisOver the last decade pharmacology has been developing computational methods to enhance drug development and testing. A computational method called network pharmacology uses graph analysis tools to determine protein target sets that can lead on better targeted drugs for diseases as Cancer. One promising area of network-based pharmacology is the detection of protein groups that can produce better e ects if they are targeted together by drugs. However, the e cient prediction of such protein combinations is still a bottleneck in the area of computational biology. The computational burden of the algorithms used by such protein prediction strategies to characterise the importance of such proteins consists an additional challenge for the eld of network pharmacology. Such computationally expensive graph algorithms as the all pairs shortest path (APSP) computation can a ect the overall drug discovery process as needed network analysis results cannot be given on time. An ideal solution for these highly intensive computations could be the use of super-computing. However, graph algorithms have datadriven computation dictated by the structure of the graph and this can lead to low compute capacity utilisation with execution times dominated by memory latency. Therefore, this thesis seeks optimised solutions for the real-world graph problems of critical node detection and e ectiveness characterisation emerged from the collaboration with a pioneer company in the eld of network pharmacology as part of a Knowledge Transfer Partnership (KTP) / Secondment (KTS). In particular, we examine how genetic algorithms could bene t the prediction of protein complexes where their removal could produce a more e ective 'druggable' impact. Furthermore, we investigate how the problem of all pairs shortest path (APSP) computation can be bene ted by the use of emerging parallel hardware architectures as GPU- and FPGA- desktop-based accelerators. In particular, we address the problem of critical node detection with the development of a heuristic search method. It is based on a genetic algorithm that computes optimised node combinations where their removal causes greater impact than common impact analysis strategies. Furthermore, we design a general pattern for parallel network analysis on multi-core architectures that considers graph's embedded properties. It is a divide and conquer approach that decomposes a graph into smaller subgraphs based on its strongly connected components and computes the all pairs shortest paths concurrently on GPU. Furthermore, we use linear algebra to design an APSP approach based on the BFS algorithm. We use algebraic expressions to transform the problem of path computation to multiple independent matrix-vector multiplications that are executed concurrently on FPGA. Finally, we analyse how the optimised solutions of perturbation analysis and parallel graph processing provided in this thesis will impact the drug discovery process.This research was part of a Knowledge Transfer Partnership (KTP) and Knowledge Transfer Secondment (KTS) between e-therapeutics PLC and Newcastle University. It was supported as a collaborative project by e-therapeutics PLC and Technology Strategy boar

Scoliosis and Spinal Disorders journal: a new, cutting-edge frontier in spine publishing

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