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Dataset for the publication 'Effect of laser repetition rate on the growth of Sc2O3 via pulsed laser deposition'
No full textDataset to support Effect of laser repetition rate on the growth of Sc2O3 via pulsed laser deposition published in Applied Physics A
This dataset contains the data associated to figure 3-8 in the from of spreadsheets. </span
Characterisation and laser performance of a Yb:LuAG double-clad planar waveguide grown by pulsed laser deposition
No full textWe report on the fabrication of a crystalline multi-layer lutetium aluminium garnet planar waveguide, with a ytterbium-doped core, via hetero-epitaxial pulsed laser deposition on an undoped yttrium aluminium garnet substrate. Physical and optical characterization of the device revealed good crystallinity of the grown films and mode propagation investigations confirmed waveguiding properties. The measured fluorescence lifetime and calculated absorption and stimulated emission cross section spectra are found to be comparable with those reported for Yb:LuAG crystals grown by traditional methods. When end-pumped by a diode-laser bar, the crystalline double-clad Yb:LuAG planar waveguide lased using a quasi-monolithic cavity configuration. An output power of > 3 W with a 20% slope efficiency was obtained, limited by a waveguide propagation loss of 1.2 dB cm−1. This first demonstration of a multi-layer LuAG double-clad planar waveguide laser shows great potential for realising compact high-power waveguide lasers and amplifiers.</p
Effect of laser repetition rate on the growth of Sc<sub>2</sub>O<sub>3</sub> via pulsed laser deposition
No full textThis paper reports a study of the effect of laser pulse repetition rate and substrate temperature on the properties of crystalline Sc2O3 films grown on <0001>-oriented sapphire via pulsed laser deposition (PLD). For the range of substrate laser-heating powers investigated, optimum <111>-film growth was obtained at the highest available repetition rate of 100 Hz. Scanning electron microscopy and X-ray diffraction measurements revealed that a decrease in the repetition rate favours highly textured/island growth. The repetition rate was also proven to affect the lattice constant of the films, with a difference up to 0.3% between the films grown at high and low repetition rates. The general trend indicates that the out-of-plane lattice constant of the film shifts closer to the bulk value when the pulse repetition rate is increased. However, the lattice constant could also be reduced through in-situ post-growth annealing, which had the additional benefit of reducing the width of the (222) rocking curve peak. This work provides further evidence that energetic-PLD dynamics leads to higher quality PLD-grown crystalline films and for this material undermines the old adage that lower pulse repetition rates lead to higher quality thin-film crystalline growth
Pulsed laser deposition of crystalline garnet waveguides at a growth rate of 20 µm per hour
No full textWe report pulsed laser deposition of high-quality crystalline yttrium aluminium oxide and yttrium gallium oxide with a growth rate approaching 20 μm per hour by using an excimer laser operating at a repetition rate of 100 Hz. This result demonstrates the capability of PLD at 100 Hz for upscaling deposition speeds to a rate that is industrially relevant. In addition, we show that use of this high repetition rate can cause additional heating of the substrate, which in turn affects the film composition. This effect is used as an additional control parameter on the composition, and thus refractive index, of the grown material
Yb-doped mixed sesquioxide thin films grown by pulsed laser deposition
No full textGrowth and characterization of compositionally tuned, ytterbium-doped mixed lutetium-scandium oxide, and pure lutetia and scandia crystalline films are presented. Pulsed laser deposition was employed to grow these sesquioxide films, of thicknesses up to 20 µm, on (0001)-sapphire substrates. Varying the atomic ratio of lutetium to scandium in the target, the lattice parameter of the resulting films could be tuned to match that of the single-crystal c-cut sapphire substrate to achieve a lattice mismatch of <0.1%. Optimization of growth parameters led to a reduction of undesirable particulates and scattering points within the film. X-ray diffraction measurements show (222) orientated epitaxial growth with crystallinity comparable to bulk crystals. Through pole figure and electron-backscatter imaging measurements, it was found that two inverted cubic lattice orientations grow with micron-scaled domains. Growth of these lattice- matched mixed sesquioxides paves the way for high quality waveguides for generation of ultrashort laser pulses
Particulate reduction in ternary-compound film growth via pulsed laser deposition from segmented binary-targets
No full textWe present the hetero-epitaxial growth of high-quality crystalline Y3Ga5O12 onto a <100>-oriented YAG substrate via pulsed laser deposition, using mixed ternary-compound and segmented binary-compound targets. We observe that a Y3Ga5O12 film fabricated using a segmented target (Y2O3/Ga2O3) contained ~ 100 times fewer scattering points than a film grown using a mixed Y3Ga5O12 target. We show that following ablation, the surface of the mixed compound (ternary) target had laser-induced cone structures, whereas the surface of single compound (binary) targets did not. It is concluded that the different ablation dynamics of the oxide constituents in the respective targets plays a significant role in the origin of the scattering points in the resultant films
Student-led outreach and public engagement activities at the University of Southampton to celebrate the inaugural International Day of Light
No full textThe 16th May 2018 marks the first annual International Day of Light (IDL). The steering committee of the IDL initiative encouraged grassroots activities to increase the awareness and understanding of the applications of light. One such undertaking is the program of events developed by the postgraduate students of the Optoelectronics Research Centre (ORC) at the University of Southampton (UoS). The program focused on engaging with the public and local schools with low levels of progression to higher education. Three events were designed: an outreach masterclass, combining activities and demonstrations from well-established workshops covering light in telecommunications, manufacturing and medicine; an art competition in a local school, for students to express scientific knowledge in a creative way; and a public panel, to explore the uses of light in a multitude of disciplines and open academic research to a broader audience. This paper explains how the events built on the ORC students’ long history of outreach and the legacy of the International Year of Light. Each event is outlined in detail, explaining the objectives and the rationale behind the audience selection. The program outcomes are described, including the impact, the methods employed and the utilization of expert partners to increase the program reach (commercial media, local schools and UoS’s diversity and inclusion outreach department), and the lessons learned from the program are assessed. These experiences can be used to recycle and adapt this format for other grassroots IDL programs. This project received funding through a SPIE IDL Micro Grant
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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