1,721,007 research outputs found
Data supporting the publication 'Tunable on-chip optical traps for levitating particles based on single-layer metasurface'
No full textThis dataset provides the initial data of the figures shown in the paper named 'Tunable on-chip optical traps for levitating particles based on single-layer metasurface', published in Nanophotonics
https://doi.org/10.1515/nanoph-2023-0873
This dataset contains an excel file including all initial data for plotting the curves in above publication via multiple sheets. The data was generated by the numerical simulation method and parameter conditions provided in above publications.
Lumerical FDTD and MATLAB softwares are adopted to generate the data.
Related projects: EPSRC EP/V000624/1</span
All-dielectric metasurface for optical manipulation and advanced imaging application
No full textMetasurface which is made up of an array of sub-wavelength meta-atoms on a flat substrate is powerful of engineering light beam’s amplitude, phase, polarization, and frequency. It attracts increasing attentions in optical manipulation, communication, imaging, and metrology fields. To boost the metasurface’s applications in classical regime, the working principle, general design process, and fabrication flow of an all-dielectric metasurface are firstly studied in this thesis. Three working regimes of the metasurface are clearly classified. Except for the two conventional working regimes (polarization-independent regime and classical spin-multiplexing regime), a non-classical spin-multiplexing regime is explored to achieve multifunctional imaging system via a low refraction index metalens. In polarization-independent working regime, a near infrared (NIR) metalens is achieved to levitate and trap a nanorod in a vacuum. In experiment, both the translation and rotation motion of levitated nanorod can be precisely controlled by the laser beam’s polarization and power as well as the vacuum pressure. To construct an optically coupled dynamics system, a NIR dual foci metalens is achieved in the classical spin-multiplexing working regime for levitating two particles. Experiment results illustrate that the two optical potential wells can be precisely tuned, and two nanoparticles can be stably levitated at a close distance. Based on above experimental results, the world first prototype of metalens-based levitated optomechanical sensor is invented.In classical spin-multiplexing working regime, two dual-mode microscopes with a high magnification of 58X, a 600μm × 800μm field of view (FOV), and a diffraction-limited resolution are obtained via a NIR metalens where the focal point can be tuned to vortex ring from a Gaussian spot. In addition, a unified design frame is proposed to polarization-controlled generate arbitrary vector vortex beams on a HOPS and a HyOPS. In the proof of concept experiment in NIR, non-focused and tightly focused 5th order HOPS beams are firstly demonstrated. Then, tightly focused 0-1-order and 0-2-order HyOPS beams are controlled generated to comparatively study the focusing property of integer-order and fractional-order vector vortex beams. In non-classical spin-multiplexing working regime, it is the world first to achieve tri-foci metalens based on low-refraction-index material (i.e., Si3N4). An infinity-corrected microscope with three large magnifications and resolutions is firstly integrated into a centimetre-scale device via a longitudinal tri-foci Si3N4 metalens. Then, a compact simultaneously achiral and chiral microscope with a magnification of 53X is experimentally demonstrated to realize all-optics fast identification of biological and chemical sample’s chirality via a lateral Si3N4 tri-foci metalens.<br/
A hybrid method to calculate optical torque: application to a nano-dumbbell trapped by a metalens
No full textThe hyper-fast rotation frequency realized in an optical levitation system provides an essential platform for various applications. Benefiting from the development of integrated photonics, optically trapping and manipulating a micro-particle via a metalens has been a significant development trend. The metalens' powerful and flexible controlling ability of the optical field opens the door to tailoring optical trapping potential. However, the existing methods are difficult to compute optical forces and torques on a non-spherical particle trapped by a metalens-based trapping system, especially when the trapping potential is tailored by a delicately designed metalens. Therefore, a hybrid method by combining the finite difference in time-domain and discrete dipole approximation method is proposed in this paper to realize this goal. The relative error of this method is verified to be below 10%. Based on this hybrid method, the fractional vortex field is found in a metalens-based trapping system for the first time. Then, the optical torque's dependency on a nano-dumbbell's geometrical parameters and spatial orientation angles are studied. It is found that there is a torque driving the nano-dumbbell to rotate about the optical axis, and the long axis of the nano-dumbbell tends to be aligned to the polarization plane because of the transverse optical torques if the long axis of the nano-dumbbell is not aligned to the optical axis.</p
RAM-adaptive parallel generating and minimizing the layout file of wafer-scale metalens
No full textMetalens have emerged as an attractive device for astronomy observation because of their submillimeter thickness and lightweight as well as their powerful manipulating ability of light field’s amplitude, phase, and polarisation. However, the aperture size of a metalens is restricted within a millimetre scale by the layout file sizes. Here, we introduce the OASIS format to effectively reduce the layout file sizes and propose a RAM-adaptive parallel approach for accelerating the layout file generation of large-aperture metalens. By designing a metalens working in the wavelength of 1550nm, we demonstrate that the layout file sizes can be reduced by 94% via using OASIS format than conventional GDS format. Based on a multiple-core computer, the OASIS layout file of a 5cm-diameter metalens can be generated within 10 hours
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
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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