1,720,989 research outputs found
Cavity solitons synchronization
No full textBy modulating two cavity solitons (CSs) locally, in a driven vertical cavity surface emitting laser above threshold, we forced them to oscillate sinusoidally in time. It is illustrated that the amplitude of modulation of two CSs plays an important role in their synchronization. We show that the oscillations of two CSs can be synchronized only when the interaction of them is highly nonsymmetrical and the difference of the modulation frequencies is at most of the order of 1 GHz. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE
Enhanced resonance frequency and modulation bandwidth in a cavity soliton laser
No full textCavity solitons in a driven vertical-cavity surface-emitting laser (VCSEL) above threshold can amplify the modulation of the injected field over a bandwidth larger than 100 GHz by exploiting the combined low frequency amplification of a bistable optical system with the enhanced relaxation oscillation frequency of an injection-locked laser
All-optical tunable delay-line memory based on a semiconductor cavity-soliton laser
No full textCavity soliton lasers in a vertical-cavity surface-emitting laser with a saturable absorber can spontaneously move provided that a proper ratio of the carrier lifetimes in the amplifier and in the absorber is considered. Use is made of this fact to propose a scheme based on which a tunable all-optical delay line can be demonstrated. This easy-to-realize delay device exhibits high delay range, a very good delay resolution, and a wide extent of available data bandwidth. Also it is shown that the ratio of delay time to pulse duration (fractional delay) can be as large as 2300
Control of spatiotemporal rogue waves by harmonic pump modulation in a semiconductor laser with a saturable absorber
Get PDFThrough numerical simulations, statistical and dynamical properties of extreme events in a broad-area semiconductor laser with intracavity saturable absorber are investigated. By inclusion of a diffusion coefficient for the field, formation of rogue waves in a state of extended turbulence is studied and shown to be affected by harmonic perturbations. In particular, we propose a control technique based on periodic modulation of the pump parameter which can either drive the state of the system closer to or away from the chaotic attractors respectively enhancing or suppressing the generation of rogue waves. By statistical and dynamical analysis of the events in terms of intensity and optical gain, we show that when the system is under resonant modulation with frequency close to that of the dominant oscillations in the turbulent state (which is equal to the relaxation oscillation frequency typical of semiconductor lasers), more rogue waves are triggered with larger intensities and shorter lifetimes. On the other hand, off-resonant modulations restrain the formation of rogue waves where they appear in lower intensities and longer lifetimes. An example of special cases where the proposed scheme can completely forbid or allow the emission of rogue waves is also presented
The study of twin phase solitons interaction and switching
No full textCavity solitons as part of dissipative localized structures have been of great interest. In cavity, there must be the double balance between dispersion phenomenon and nonlinear phenomena and at the same time the cavity losses are made up for by pumping continuous-wave coherent driving which leads to the formation of Spatio-temporal soliton. In previous studies z direction has neglected in the cavity. By taking into account of this direction the new type of solitons named “phase soliton” is introduced. In this paper, we studied the ring cavity in more detail and the intraction of duble phase soliton. We find out, switching ON and OFF process of phase soliton. Also the optimal conditions for switching ON/OFF was determined. © 2022, Isfahan University of Technology
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
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