1,721,048 research outputs found
Nonlinear tapered holey fibers with high stimulated Brillouin scattering threshold and controlled dispersion
No full textWe numerically calculate optical property maps for hexagonally arranged nonlinear holey fibers made of silica, lead silicate, and bismuth oxide-based glass and employ them to design tapered fibers with enhanced stimulated Brillouin scattering threshold and a simultaneous control of the average dispersion
System applications of holey fibers
No full textThe wavelength-scale features in holey fibers lead to novel properties including endlessly single-mode guidance, high optical nonlinearity. The current HF technology for a wide range of device applications in optical communication systems is reviewed
Applications of Raman effect in holey fibre
No full textWe demonstrate the application of Raman effect in Holey Fibre (HF) to produce an efficient Raman amplifier and modulator. Using a 75m long HF with an effective are of 2.85 µm2 we obtained internal gain of over 42dB for the amplifier and 11dB extinction ratio for the modulator
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
Reconfigurable Phase Shifted Fiber Bragg Grating Using Localized Micro-Strain
No full textA simple and precise method for tuning of localized phase shift in fiber Bragg grating (FBG) using mechanical micro-strain is proposed and experimentally verified. Positive and negative continuous phase shifts tuning between 0 and +π/-π in a uniform FBG is experimentally demonstrated using confined micro-strain in a beam bending configuration. The magnitudes of the temporary phase shifts can be linearly controlled by changing the load displacement, with set-and-forget capability
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
A holey fiber based WDM wavelength converter incorporating an apodized fiber Bragg grating filter
No full textWe demonstrate a tunable WDM wavelength converter based on XPM in just 6m of highly nonlinear holey fiber and incorporating a precise, compression tuned apodized fiber-grating filter. We achieve broadband 10Gbit/s wavelength conversion (~20nm) with a constant pulsewidth due to short device length and correspondingly reduced pulse walk-off effects
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Raman effects in a highly nonlinear holey fiber: amplification and modulation
No full textWe experimentally demonstrate that a short length of highly nonlinear holey fiber (HF) can be used for strong L+-band (1610-1640-nm) Raman amplification and ultrafast signal modulation. We use a pure silica HF with an effective area of just 2.85 mum(2) at 1550 nm, which yields an effective nonlinearity similar to15 times higher than in conventional silica dispersion-shifted fiber. Using a 75-m length of this fiber, we obtained internal Raman gains of more than 42 dB and a noise figure of similar to6 dB under a forward single-pump scheme, and the Raman gain coefficient was experimentally estimated to be 7.6 X 10(14) m/W. Also. an 11-dB signal extinction ratio in a Raman-induced all-optical modulation experiment was achieved with the same fiber. (C) 2002 Optical Society of America
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