1,720,958 research outputs found
Four-Wave Mixing Processes in a Photonic Molecule Reconfigured by Micro-Electro-Mechanical System(MEMS)
No full textSilicon photonics; Four-wave mixing; Photonic integrated circuit; Micro-electro-mechanical systems (MEMS); Coupled-resonator optical waveguide (CROW)Microring resonators intensify the four-wave mixing (FWM) process, a crucial nonlinear optical phenomenon, owing to their ability to enhance optical power significantly. Nonetheless, traditional resonators in integrated photonics typically encounter difficulties with accurately adjusting coupling intensities and phases. Addressing this, we introduce a pioneering, fully reconfigurable photonic molecule device, empowered by electrostatic micro-electro-mechanical systems (MEMS), which provides unparalleled control over both the coupling strength and resonant wavelengths of each microring for the first time.
This novel device, operated through low-power electrostatic MEMS, incorporates tunable directional couplers and phase shifters for each microring, exemplifying its utility as a photonic molecule and establishing its functionality as a coupled-resonator optical waveguide (CROW) filter. Our experimental analysis reveals that this extensive tunability shows the complex interaction between the two resonances of microrings, confirming its proficiency as a photonic molecule device and enabling FWM across all wavelengths. a seeded FWM has been successfully demonstrated with a conversion efficiency of -56 dB at a pump power of 7.3 dBm, underscoring the device's significant potential in enhancing optical applications.
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초소형 링 공진기는 강한 광학적 세기 증가 특성을 이용해 중요한 비선형 광학 현상인 네 파장 혼합 과정을 강화합니다. 그럼에도 불구하고, 광 직접 회로를 구성하는 기존의 공진기들은 결합 강도와 위상을 정확하게 조절하는 데 어려움이 있습니다. 이에 대응하여, 우리는 정전기력 기반의 마이크로미터 크기의 전기기계 시스템(멤스)을 이용해 각 초소형 링의 결합 강도와 공진 파장을 정밀하게 제어할 수 있는 완전히 재구성 가능한 광자 분자 장치를 처음으로 소개합니다.
이 새로운 장치는 각 초소형 링에 조절 가능한 방향성 결합기와 위상 변환기를 결합하여 설계되었습니다. 이 장치는 매우 낮은 전력을 소비하는 정전기력 멤스를 활용해 효율적으로 동작하며, 광자 분자로서의 유용성을 입증하고 결합된 광학 도파로 공진기(크로우) 필터로서의 기능을 확립합니다. 실험 분석을 통해 보여준 이 광범위한 조절성은 초소형 링의 두 공진 간의 복잡한 상호 작용을 설명할 수 있고, 광자 분자 장치로서의 능력을 확인하고 임의의 파장에 대해 네 파장 혼합 과정을 가능하게 합니다. 또한 펌프 출력 7.3 dBm에서 - 56 dB의 변환 효율을 달성한 네 파장 혼합 과정은 이 장치가 광학 분야에서 응용될 중대한 잠재력을 강조합니다.Ⅰ Introduction 1
Ⅱ Device architecture 4
2.1 Device concept 4
2.1.1 Tunable directional coupler 4
2.1.2 Tunable phase shifter 8
2.1.3 Electrostatic MEMS cantilever actuator 11
2.2 MEMS-based reconfigurable photonic molecule device 14
Ⅲ Results 15
3.1 Fabrication 16
3.2 Experimental setup 21
3.3 Fundamental characterization in MEMS-based CROW 22
3.3.1 Spectral response measurement 22
3.3.2 Mechanical response measurement 26
3.3.3 Electrical power consumption 28
3.4 Nonlinear application in MEMS-based photonic molecule 30
3.4.1 Spectral response measurement 30
3.4.2 Four-wave mixing process 32
Ⅳ Future work 35
Ⅴ Conclusion 37
References 38
요 약 문 41MasterdCollectio
Programmable photonic arrays based on microelectromechanical elements with femtowatt-level standby power consumption
No full textProgrammable photonic integrated circuits offer exciting opportunities for optoelectronic signal processing, computing and communications in a number of emerging applications in classical and quantum photonics. In this work, we show the array-level demonstration of tunable couplers and phase shifters with capacitive electrostatic microelectromechanical actuators in a recirculating mesh network. The overall fabrication process is compatible with the conventional wafer-level passive silicon photonics platform. Extremely low unit-level standby power consumption of <10 femtowatts and reconfiguration energy of <40 picojoules with <11 V programming voltages offer well-balanced, scalable routes for efficient phase and amplitude modulation of the guided lightwaves with sub-decibel optical losses. The extinction ratios of the continuously tunable directional coupler exceed 30 dB. Full 2π-phase shifting can be achieved with a modulation efficiency of less than 0.075 V cm and a phase-dependent insertion-loss variation of 0.01 dB. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.FALSEsciescopu
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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