1,721,197 research outputs found
Jørn Utzon -Influences and Reinterpretation
No full textThe Paper presents a study of Jørn Utzon's architecture, in terms of its response to both local context and transcultural influences. The paper shows Utzon to have been a precursor and direct influence upon subsequent developments within contemporary regional architecture
A review of recent progress in holmium-doped silica fibre sources
No full textIn this paper we present a review of holmium-doped silica fibre based sources. We discuss recent demonstrations of an efficient cladding-pumped fibre geometry and the impact it has made on the power scaling of these sources. We discuss the wavelength region that is addressable by holmium-doped silica based devices and highlight the advantage over thulium-doped fibres in terms of atmospheric transmission. Finally we review the development and current status of the pulsed and CW operation of holmium fibre sources and discuss the future development potential of sources in the ns-fs pulse-width range
A cladding-pumped, tunable holmium doped fiber laser
No full textWe present a tunable, high power cladding-pumped holmium doped fiber laser. The laser generated >15 W CW average power across a wavelength range of 2.043-2.171 µm, with a maximum output power of 29.7 W at 2.120 µm. The laser also produced 18.2 W when operating at 2.171 µm. To the best of our knowledge this is the highest power operation of a holmium doped laser at a wavelength >2.15 µm. We discuss the significance of background losses and fiber design for achieving efficient operation in holmium doped fibers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
High power holmium fiber lasers
No full textSources based on resonantly cladding pumped holmium-doped fibres have been demonstrated at >400 W CW or with pulse energies of >2 mJ. We review the enabling technologies, and discuss the challenges associated with high power operation of fibre lasers at 2.1 μm
High power resonantly pumped holmium-doped fibre sources
No full textHolmium-doped fibres provide a power scalable gain-medium capable of operation at wavelengths beyond 2.05 μm. We discuss and review our approach to the power scaling of pulsed and CW laser sources at 2.1 μm using holmium-doped fibres. This paper outlines experiments which demonstrate the wavelength region accessible using holmium-doped silica fibres, as well as a linearly polarised pulsed master-oscillator power amplifier and high average power CW laser and amplifier systems. These devices demonstrate the applicability of holmium fibre lasers to a range of scientific, medical, industrial and defence applications
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