2,658 research outputs found
RF or THz signals generated from DC biased multimode lasers
Although self pulsating (SP) lasers are DC biased, they feature a modulation of the output power. For the results presented in this paper, the SP frequency corresponds to the frequency spacing between longitudinal modes or its second harmonic. The performances of both a 40 GHz self pulsating distributed Bragg reflector laser and of a 660 GHz slotted laser are presented. For the first laser, the radio frequency (RF) signal was analysed on electrical spectrum analyser and its linewidth was smaller that the sum of the main optical modes, proving a passive modelocking of the mode phases. For the slotted laser, a bolometer interfaced to a FT IR spectrometer is used for the terahertz (THz) detection. A signal 10 times larger than the noise level was measured with this set up. Both lasers have demonstrated to be an easy solution to produce RF or THz signal generator
Investigation of in-situ parameter control in novel semiconductor optical amplifiers
Fibre optic networks form the backbone of modern communications systems. As demand for ever increasing bandwidth continues to grow, technologies that enable the
expansion of optical networks will be the key to future development. The semiconductor optical amplifier (SOA) is a technology that may be crucial in future optical networks, as a low cost in-line amplifier or as a functional element. As fibre networks extend closer to the end user, economical ways of improving the reach of these networks are
important. SOAs are small, relatively inexpensive and can be readily integrated in photonic circuits. Problems persist with the development of SOAs, however, in the form
of a relatively high noise figure and low saturation output power, which limits their use in many circumstances. The aim of this thesis is to outline a concept for control of these parameters such that the SOA can achieve the performance required. The concept relies on the control of the carrier density distribution in the SOA. The basic characteristics of the SOA and how they are affected by changes in the carrier density are studied. The performance of the SOA in linear and high power transmission of CW and pulsed signals is determined. Finally, the wavelength conversion characteristics of the SOA are outlined. The role of the carrier density control in shaping all of these characteristics will be explained
Samuel Beckett and the Writers of Port-Royal
It has been observed that ‘the literary influences on Beckett have been far more important than has been acknowledged, and more important indeed, than the philosophical influences’ (Smith 2002: 3). The truth of this statement is evidenced by the description that scholars have given of Samuel Beckett’s relationship to seventeenth century French classicism. To date, critical interest has been limited for the most part to the figure of the philosopher René Descartes on the (fragile) grounds that Beckett was exclusively concerned with the Cartesian imperative of clarity and order, the fundamental dualism between body and mind, and Nominalism.
Together with the assumption that Beckett’s vision was essentially Cartesian, his literary filiation with Pascal was suggested by critics, but only in terms of Beckett’s formal approach to the theatre. In his short article on En attendant Godot in 1953, the playwright Jean Anouilh was among the first reviewers to suggest that Beckett’s drama synthesizes the encounter between ‘classicism’ and a ‘modern’ form of art. It is well known that Beckett retained a lifelong admiration for Pascal – indeed, Pascal was one of his ‘old chestnuts’ (Knowlson 1997: 653). Little attention has been paid, however, to the originality of Pascal’s thought, the specific nature of his prose, and the impact these might have had upon Beckett’s mature work, especially the trilogy and the subsequent short prose. Yet, in the literary and philosophical context of post-war France, Beckett’s filiation with Pascal, their corresponding preoccupations, were evident to his contemporaries, who identified Pascal as an underlying presence in his works
Sabil and Wikala of Dhul Fiqar Oda Bashi
interior, courtyard, "Vue de l'Okel Zoulfiqar," color plate XLIV of Pascal Coste's "Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826", 1818-182
First person - Aude Pascal
International audienceFirst Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Aude Pascal is first author on `Annexin A2 and Ahnak control cortical NuMA-dynein localization and mitotic spindle orientation', published in JCS. Aude is a research assistant in the lab of Re ' gis Giet at University of Rennes, France, who is particularly interested in developmental biology. She has always been struck by the fact that a whole organism displaying multiple functions arises from a single cell. For this reason, she has oriented her research on mitosis and meiosis to study the different steps, components and structures involved in these processes
Pascal Tutorial, 1987
There exists a limited number of tutorials for the Pascal programming language using the Apple Computer. The demand for these tutorials exceeds the supply. In this thesis an attempt was made to rectify this shortage by designing a Pascal tutorial for the Apple computer. This Pascal tutorial is designed to assist with instructing an introductory computer programming course in Pascal, incorporating Apple Superpilot as the authoring language. Emphasis is placed on making the program "user friendly." A person with no previous programming experience should be able to easily execute this tutorial. The information presented as the subject matter of the tutorial will follow the guidelines recommended by the Association for Computing Machinery
Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826
general view, "Vue des Tombeaux au Nord-Est de la Ville," color plate LXIII of Pascal Coste's "Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826", 1818-182
Gamia el-Muaiyad
interior, qibla wall, "Vue de la Niche du Sanctuaire et de la Chaire de la Mosquee el Moyed"," color plate XXVIII of Pascal Coste's "Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826", 1818-182
Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826
section, section of the prayer hall, and details of inscription and chandelier, Plate XXIII of Pascal Coste's "Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826
Tomb of the Family of Muhammad 'Ali
interior, "Vue des Tombeaux de la Famille de Mohamed-Aly-Pacha, dans le Cimetiere de l'Imam," color plate LXIV of Pascal Coste's "Architecture arabe; ou, Monuments du Kaire, mesurés et dessinés, de 1818 à 1826", 1818-182
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