143 research outputs found

    Europeanizing territoriality—towards soft spaces?

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    This paper explores the coexistence of relational and territorial spaces—soft spaces—through the experiences of EU integration and territorialization. First, we seek a better understanding of EU integration through an engagement with the literature and research on soft spaces. We propose that EU integration is best understood as involving an interplay between territorial and relational understandings and approaches that vary through time, a variation that can be categorized as involving pooled territoriality, supraterritoriality, and nonterritoriality. Second, we seek to add to the current research and literature on soft spaces by focusing upon the changing character of soft spaces and their temporalities. We approach these two dimensions through an exploration of two ex post case studies, the development of which typically shows different stages of softening, hardening, and of differing degrees of Europeanization. With the focus on Europeanization, the paper concludes with three findings: the new spaces of European territoriality are characterized by, first, temporal dynamics, second, their parallel existence with ‘hard’ spaces, and, finally, they can be employed as a political tool. NoneThis is the Author Accepted Manuscript of Allmendinger, P., Chilla, T., and Sielker, F. 2014. The final version is available at http://www.envplan.com/abstract.cgi?id=a130037p

    Saturation intensity and time response of InGaAs-InGaP MQW optical modulators

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    Includes bibliographical references (page 260).We report modulation saturation and time response measurements on InGaAs-InGaP MQW modulators. The measurements yield a saturation intensity of (3.7 ± 0.1) kW/cm2 for a 0-10 V swing and switching times between 10 and 90 ns, depending on the bias voltage and incident light intensity. The observed dependence indicates that field screening due to carrier build-up is the dominant physical mechanism determining both the speed and the saturation intensity. This conclusion is supported by results of theoretical calculations

    Homodyne detection for measuring internal quantum correlations of optical pulses

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    A new method is described for determining the quantum correlations at different times in optical pulses by using balanced homodyne detection. The signal pulse and sequences of ultrashort test pulses are superimposed, where for chosen distances between the test pulses their relative phases and intensities are varied from measurement to measurement. The correlation statistics of the signal pulse is obtained from the time-integrated difference photocurrents measured.Comment: 7 pages, A4.sty include

    Vertical-external-cavity surface-emitting lasers and quantum dot lasers

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    The use of cavity to manipulate photon emission of quantum dots (QDs) has been opening unprecedented opportunities for realizing quantum functional nanophotonic devices and also quantum information devices. In particular, in the field of semiconductor lasers, QDs were introduced as a superior alternative to quantum wells to suppress the temperature dependence of the threshold current in vertical-external-cavity surface-emitting lasers (VECSELs). In this work, a review of properties and development of semiconductor VECSEL devices and QD laser devices is given. Based on the features of VECSEL devices, the main emphasis is put on the recent development of technological approach on semiconductor QD VECSELs. Then, from the viewpoint of both single QD nanolaser and cavity quantum electrodynamics (QED), a single-QD-cavity system resulting from the strong coupling of QD cavity is presented. A difference of this review from the other existing works on semiconductor VECSEL devices is that we will cover both the fundamental aspects and technological approaches of QD VECSEL devices. And lastly, the presented review here has provided a deep insight into useful guideline for the development of QD VECSEL technology and future quantum functional nanophotonic devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with arXiv:0904.369

    Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging

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