1,720,982 research outputs found
Ultraviolet laser written devices for quantum photonics
No full textPhotonic platforms play a key role in quantum technology. Silicon nitride integrated photonics is emerging as a promising photonic quantum platform due to its low loss and ease of integration into semiconductor fabrication pipelines. Photonic crystal fibre can be a practical quantum light source for photonic-based quantum networks. This thesis explores controlled UV exposure, applied to these these two platforms, as well as commercial fibre for advancing quantum technology. In this thesis, fibre Bragg gratings are UV written into PCF, integrating filtering for single photon sources. Fibre Bragg gratings are also fabricated in PCF with the goal of making a fibre optical parametric oscillator. This is to be used to generate a squeezed vacuum. Additionally, in this work, silicon nitride UV photosensitivity is demonstrated and quantitatively investigated in both PECVD and LPCVD silicon nitride layers. The latter is achieved by applying hydrogen loading. The maximum refractive index changes in these layers are found to be 0.05 and 0.006, respectively. This allows for the passive fine-tuning of resonant components, such as ring resonators and MZIs on chips, which are interesting for quantum photonic circuits. This mechanism also allows for the first demonstration of laser-written Bragg gratings in silicon nitride. A refractive index modulation of 2.4x10−4 is shown, comparable to that typically used in Ge-doped fibre Bragg gratings. This thesis also investigates the use of fibre Bragg gratings in commercial fibre for new single-photon pair generation applications. Two proposals are made. The first is the use of π-phase shifted, 3rd order Moiré gratings for use as a short, fibre pair source of high purity, narrow spectral width and enhanced brightness. For this, a model of triply resonant spontaneous four-wave mixing is constructed. The second proposal is the use of the intra-cavity field of a fibre Brillouin laser as a source of pump light for photon pair generation. The second is experimentally tested and shown to produce correlated pairs using low pump powers in SMF 28 fibre
Dataset supporting the University of Southampton Doctoral Thesis "Passive and Active Tunability of the Silicon Nitride platform"
No full text Dataset supporting the University of Southampton Doctoral Thesis "Passive and active tunability of the silicon nitride platform"
This dataset contains: numerical data used to create the graphs present in the thesis, all in .csv format. The data includes simulation, material analysis, optical and electrical characterisation of devices.
The data is embargoed to 30/04/2025</span
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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