1,720,995 research outputs found
Dispersion measurement assisted by a stimulated parametric process
No full textDispersion plays a major role in the behavior of light inside photonic devices. Current state-of-the-art dispersion measurement techniques utilize linear interferometers that can be applied to devices with small dispersion-length products. However, linear interferometry often requires beam alignment and phase stabilization. Recently, common-path nonlinear interferometers in the spontaneous regime have been used to demonstrate alignment-free and phase-stable dispersion measurements. However, they require single-photon detectors, resulting in high system cost and long integration times. We overcome these issues by utilizing a nonlinear interferometer in the stimulated regime and demonstrate the ability to measure the dispersion of a device with a dispersion-length product as small as 0.009 ps/nm at a precision of 0.0002 ps/nm. Moreover, this regime allows us to measure dispersion with shorter integration times (in comparison to the spontaneous regime) and conventional optical components and detectors
Tailoring second-harmonic generation in birefringent poled fiber via Twist
No full textWe predict theoretically and demonstrate experimentally the ability to generate and control the strengths of various second-harmonic signals in birefringent poled fiber. This is done by simply twisting the fiber
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
Quantum interferometry through cascading broadband entanglement sources
No full textWe demonstrate broadband (~100nm) quantum interference in telecom frequencies in an all-fiber system with cascaded SPDC sources. Its applications in dispersion metrology and quantum state engineering are also demonstrated.</p
Biphoton shaping with cascaded entanglement sources
No full textWe experimentally demonstrate the ability to simultaneously tune the spectral and polarization properties of biphotons through cascading two biphoton sources and altering the dispersion and birefringence properties of the medium in between
Enhanced Nonlinear Optical Response From A Stee And Gently Sloping Low Relief Surface: What Is The Difference?
No full textThe second-order effective nonlinear susceptibility of a low relief interface between two media with nonlinear susceptibilities is calculated analytically for the cases of steep and gently sloping elongated periodical irregularities. An enhancement of the nonlinearity occurs for steep relief irregularities only under a sufficiently large ratio of the linear dielectric permittivities of these media.274264268Garnett, M., (1904) Phil.Trans.R.Soc.,London, 203, p. 385Haus, J.W., Ingura, R., Bowden, C.W., (1989) Phys. Rev. A., 40, p. 5729Chelma, D.S., Miller, D.A.B., (1986) Opt. Lett., 11, p. 522Sipe, J.P., Boyd, R.W., (1992) Phys.Rev.A, 46, p. 1614Boyd, R.W., Sipe, J.E., (1994) JOSA, B11, p. 297Fisher, G.L., Boyd, R.W., Gehr, R.J., Jenekle, S.A., Osaheni, J.A., Sipe, J.E., Weller- Brophy, L.A., (1995) Phys. Rev. Lett., 74, p. 1871Vitlina, R.Z., Dykhne, A.M., (1991) Sov.Phys. JETP, 72 (6), p. 983Vitlina, R.Z., (1991) Sov. Phys. Poverhnost, 3, p. 50Aspnes, D.E., (1990) Phys. Rev., B41, p. 1033
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
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