bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exact mapping between a laser network loss rate and the classical XY Hamiltonian by laser loss control
Authors: Gershenzon Igor , Arwas Geva , Gadasi Sagie , Tradonsky Chene , Friesem Asher , Raz Oren , Davidson Nir 
Published: June 2020

AbstractRecently, there has been growing interest in the utilization of physical systems as heuristic optimizers for classical spin Hamiltonians. A prominent approach employs gain-dissipative optical oscillator networks for this purpose. Unfortunately, these systems inherently suffer from an inexact mapping between the oscillator network loss rate and the spin Hamiltonian due to additional degrees of freedom present in the system such as oscillation amplitude. In this work, we theoretically analyze and experimentally demonstrate a scheme for the alleviation of this difficulty. The scheme involves control over the laser oscillator amplitude through modification of individual laser oscillator loss. We demonstrate this approach in a laser network classical XY model simulator based on a digital degenerate cavity laser. We prove that for each XY model energy minimum there corresponds a unique set of laser loss values that leads to a network state with identical oscillation amplitudes and to phase values that coincide with the XY model minimum. We experimentally demonstrate an eight fold improvement in the deviation from the minimal XY energy by employing our proposed solution scheme.
High-quality micropattern printing by interlacing-pattern holographic femtosecond pulses
Authors: Wang Zhipeng , Li Xiaowei , Jiang Lan , Li Bohong , Wei Qunshuo , Huang Lingling , Wang Zhi , Yin Jiangang , Lu Jiangang 
Published: June 2020

Abstract
To improve the efficiency of femtosecond laser direct writing, holographic femtosecond laser patterning using spatial light modulators has been widely used for the processing of micro/nanopatterns. However, the speckle noise of modulated optical fields severely limits the quality of fabricated patterns. We present a simple and effective method which involves interlacing a target pattern into a series of target subpatterns that consist of spaced spots to solve this problem. The separation of spots weakens the random interference between adjacent spots of optical fields, so the speckle noise reduces effectively, which improves the uniformity of the modulated optical fields and makes the fabricated patterns with high quality. With optimal interlacing numbers, complex micropattern arrays containing curved edges and sophisticated structures can be fabricated with superior quality and high efficiency. Binary holograms with improved optical characterization are realized by using the interlacing-pattern method, revealing the extensive potential of this method in micropattern processing and functional device fabrication with high quality and efficiency.
Recent advances in mode-locked fiber lasers based on two-dimensional materials
Authors: Wang Junli , Wang Xiaoli , Lei Jingjing , Ma Mengyuan , Wang Cong , Ge Yanqi , Wei Zhiyi 
Published: June 2020

Abstract
Due to the unique properties of two-dimensional (2D) materials, much attention has been paid to the exploration and application of 2D materials. In this review, we focus on the application of 2D materials in mode-locked fiber lasers. We summarize the synthesis methods for 2D materials, fiber integration with 2D materials and 2D materials based saturable absorbers. We discuss the performance of the diverse mode-locked fiber lasers in the typical operating wavelength such as 1, 1.5, 2 and 3 μm. Finally, a summary and outlook of the further applications of the new materials in mode-locked fiber lasers are presented.
Superlattice nonlinearities for Gigahertz-Terahertz generation in harmonic multipliers
Authors: Apostolakis Apostolos , Pereira Mauro F. 
Published: June 2020

Abstract
Semiconductor superlattices are strongly nonlinear media offering several technological challenges associated with the generation of high-frequency Gigahertz radiation and very effective frequency multiplication up to several Terahertzs. However, charge accumulation, traps and interface defects lead to pronounced asymmetries in the nonlinear current flow, from which high harmonic generation stems. This problem requires a full non-perturbative solution of asymmetric current flow under irradiation, which we deliver in this paper within the Boltzmann-Bloch approach. We investigate the nonlinear output on both frequency and time domains and demonstrate a significant enhancement of even harmonics by tuning the interface quality. Moreover, we find that increasing arbitrarily the input power is not a solution for high nonlinear output, in contrast with materials described by conventional susceptibilities. There is a complex combination of asymmetry and power values leading to maximum high harmonic generation.
Polaritonic XY-Ising machine
Authors: Kalinin Kirill P. , Amo Alberto , Bloch Jacqueline , Berloff Natalia G. 
Published: June 2020

AbstractGain-dissipative systems of various physical origin have recently shown the ability to act as analogue minimisers of hard combinatorial optimisation problems. Whether or not these proposals will lead to any advantage in performance over the classical computations depends on the ability to establish controllable couplings for sufficiently dense short- and long-range interactions between the spins. Here, we propose a polaritonic XY-Ising machine based on a network of geometrically isolated polariton condensates capable of minimising discrete and continuous spin Hamiltonians. We elucidate the performance of the proposed computing platform for two types of couplings: relative and absolute. The interactions between the network nodes might be controlled by redirecting the emission between the condensates or by sending the phase information between nodes using resonant excitation. We discuss the conditions under which the proposed machine leads to a pure polariton simulator with pre-programmed couplings or results in a hybrid classical polariton simulator. We argue that the proposed architecture for the remote coupling control offers an improvement over geometrically coupled condensates in both accuracy and stability as well as increases versatility, range, and connectivity of spin Hamiltonians that can be simulated with polariton networks.
Multiphysical sensing of light, sound and microwave in a microcavity Brillouin laser
Authors: Yang Jianfan , Qin Tian , Zhang Fangxing , Chen Xianfeng , Jiang Xiaoshun , Wan Wenjie 
Published: June 2020

Abstract
Light, sound, and microwave are important tools for many interdisciplinary applications in a multi-physical environment, and they usually are inefficient to be detected simultaneously in the same physical platform. However, at the microscopic scale, these waves can unexpectedly interact with the same microstructure through resonant enhancement, making it a unique hybrid micro-system for new applications across multiple physical channels. Here we experimentally demonstrate an optomechanical microdevice based on Brillouin lasing operation in an optical microcavity as a sensitive unit to sense external light, sound, and microwave signals in the same platform. These waves can induce modulations to the microcavity Brillouin laser (MBL) in a resonance-enhanced manner through either the pressure forces including radiation pressure force or thermal absorption, allowing several novel applications such as broadband non-photovoltaic detection of light, sound-light wave mixing, and deep-subwavelength microwave imaging. These results pave the way towards on-chip integrable optomechanical solutions for sensing, free-space secure communication, and microwave imaging.
Ultra-wideband enhancement on mid-infrared fingerprint sensing for 2D materials and analytes of monolayers by a metagrating
Authors: Xie Yinong , Liu Xueying , Li Fajun , Zhu Jinfeng , Feng Naixing 
Published: June 2020

AbstractMid-infrared absorption spectroscopy is a powerful tool to identify analytes by detecting their material fingerprint in a label-free way, but it faces barriers on trace-amount analysis due to the difficulties in enhancing the broadband spectral signals. Here, we propose a sensing scheme based on the angular scanning of polarized light on a dielectric metagrating, and demonstrate it by numerical simulation. This approach not only indicates a series of significant signal enhancement factors over 30 times in an ultra-wide mid-infrared band, but also enables the explicit identification for various analytes, including 2D materials and trace-amount thin film samples. Our method would facilitate mid-infrared sensing for 2D materials and trace-amount analysis, and enable many new applications on non-destructive molecular identification.
Exploiting deep learning network in optical chirality tuning and manipulation of diffractive chiral metamaterials
Authors: Tao Zilong , Zhang Jun , You Jie , Hao Hao , Ouyang Hao , Yan Qiuquan , Du Shiyin , Zhao Zeyu , Yang Qirui , Zheng Xin , Jiang Tian 
Published: June 2020

Abstract
Deep-learning (DL) network has emerged as an important prototyping technology for the advancements of big data analytics, intelligent systems, biochemistry, physics, and nanoscience. Here, we used a DL model whose key algorithm relies on deep neural network to efficiently predict circular dichroism (CD) response in higher-order diffracted beams of two-dimensional chiral metamaterials with different parameters. To facilitate the training process of DL network in predicting chiroptical response, the traditional rigorous coupled wave analysis (RCWA) method is utilized. Notably, these T-like shaped chiral metamaterials all exhibit the strongest CD response in the third-order diffracted beams whose intensities are the smallest, when comparing up to four diffraction orders. Our comprehensive results reveal that by means of DL network, the complex and nonintuitive relations between T-like metamaterials with different chiral parameters (i. e., unit period, width, bridge length, and separation length) and their CD performances are acquired, which owns an ultrafast computational speed that is four orders of magnitude faster than RCWA and a high accuracy. The insights gained from this study may be of assistance to the applications of DL network in investigating different optical chirality in low-dimensional metamaterials and expediting the design and optimization processes for hyper-sensitive ultrathin devices and systems.
Computer generated optical volume elements by additive manufacturing
Authors: Dinc Niyazi Ulas , Lim Joowon , Kakkava Eirini , Moser Christophe , Psaltis Demetri 
Published: June 2020

AbstractComputer generated optical volume elements have been investigated for information storage, spectral filtering, and imaging applications. Advancements in additive manufacturing (3D printing) allow the fabrication of multilayered diffractive volume elements in the micro-scale. For a micro-scale multilayer design, an optimization scheme is needed to calculate the layers. The conventional way is to optimize a stack of 2D phase distributions and implement them by translating the phase into thickness variation. Optimizing directly in 3D can improve field reconstruction accuracy. Here we propose an optimization method by inverting the intended use of Learning Tomography, which is a method to reconstruct 3D phase objects from experimental recordings of 2D projections of the 3D object. The forward model in the optimization is the beam propagation method (BPM). The iterative error reduction scheme and the multilayer structure of the BPM are similar to neural networks. Therefore, this method is referred to as Learning Tomography. Here, instead of imaging an object, we reconstruct the 3D structure that performs the desired task as defined by its input-output functionality. We present the optimization methodology, the comparison by simulation work and the experimental verification of the approach. We demonstrate an optical volume element that performs angular multiplexing of two plane waves to yield two linearly polarized fiber modes in a total volume of 128 μm by 128 μm by 170 μm.
Direct routing of intensity-editable multi-beams by dual geometric phase interference in metasurface
Authors: Ding Guowen , Chen Ke , Luo Xinyao , Qian Guangxu , Zhao Junming , Jiang Tian , Feng Yijun 
Published: June 2020

Abstract
Controlling spin electromagnetic waves by ultra-thin Pancharatnam-Berry (PB) metasurfaces show promising prospects in the optical and wireless communications. One of the major challenge is to precisely control over the complex wavefronts and spatial power intensity characteristics without relying on massive algorithm optimizations, which requires independent amplitude and phase tuning. However, traditional PB phase can only provide phase control. Here, by introducing the interference of dual geometric phases, we propose a metasurface that can provide arbitrary amplitude and phase manipulations on meta-atom level for spin waves, achieving direct routing of multi-beams with desired intensity distribution. As the experimental demonstration, we design two microwave metasurfaces for respectively controlling the far-field and near-field multi-beam generations with desired spatial scatterings and power allocations, achieving full control of both sophisticated wavefronts and their energy distribution. This approach to directly generate editable spatial beam intensity with tailored wavefront may pave a way to design advanced meta-devices that can be potentially used in many real-world applications, such as multifunctional, multiple-input multiple-output and high-quality imaging devices.
Optical anapole mode in nanostructured lithium niobate for enhancing second harmonic generation
Authors: Li Yang , Huang Zhijin , Sui Zhan , Chen Huajiang , Zhang Xinyue , Huang Weian , Guan Heyuan , Qiu Wentao , Dong Jiangli , Zhu Wenguo , Yu Jianhui , Lu Huihui , Chen Zhe 
Published: June 2020

Abstract
Second harmonic generation (SHG) with a material of large transparency is an attractive way of generating coherent light sources at exotic wavelength range such as VUV, UV and visible light. It is of critical importance to improve nonlinear conversion efficiency in order to find practical applications in quantum light source and high resolution nonlinear microscopy, etc. Here an enhanced SHG with conversion efficiency up to 10−2% at SH wavelength of 282.7 nm under 11 GW/cm2 pump intensity via the excitation of anapole in lithium niobite (LiNbO3, or LN) nanodisk through the dominating d
33 nonlinear coefficient is investigated. The anapole has advantages of strongly suppressing far-field scattering and well-confined internal field which helps to boost the nonlinear conversion. Anapoles in LN nanodisk is facilitated by high index contrast between LN and substrate with properties of near-zero-index via hyperbolic metamaterial structure design. By tailoring the multi-layers structure of hyperbolic metamaterials, the anapole excitation wavelength can be tuned at different wavelengths. It indicates that an enhanced SHG can be achieved at a wide range of pump light wavelengths via different design of the epsilon-near-zero (ENZ) hyperbolic metamaterials substrates. The proposed nanostructure in this work might hold significances for the enhanced light–matter interactions at the nanoscale such as integrated optics.
Boron nitride for excitonics, nano photonics, and quantum technologies
Authors: Gil Bernard , Cassabois Guillaume , Cusco Ramon , Fugallo Giorgia , Artus Lluis 
Published: June 2020

AbstractWe review the recent progress regarding the physics and applications of boron nitride bulk crystals and its epitaxial layers in various fields. First, we highlight its importance from optoelectronics side, for simple devices operating in the deep ultraviolet, in view of sanitary applications. Emphasis will be directed towards the unusually strong efficiency of the exciton–phonon coupling in this indirect band gap semiconductor. Second, we shift towards nanophotonics, for the management of hyper-magnification and of medical imaging. Here, advantage is taken of the efficient coupling of the electromagnetic field with some of its phonons, those interacting with light at 12 and 6 µm in vacuum. Third, we present the different defects that are currently studied for their propensity to behave as single photon emitters, in the perspective to help them becoming challengers of the NV centres in diamond or of the double vacancy in silicon carbide in the field of modern and developing quantum technologies.
Spatial multiplexing holographic combiner for glasses-free augmented reality
Authors: Shi Jiacheng , Qiao Wen , Hua Jianyu , Li Ruibin , Chen Linsen 
Published: June 2020

Abstract
Glasses-free augmented reality is of great interest by fusing virtual 3D images naturally with physical world without the aid of any wearable equipment. Here we propose a large-scale spatial multiplexing holographic see-through combiner for full-color 3D display. The pixelated metagratings with varied orientation and spatial frequency discretely reconstruct the propagating lightfield. The irradiance pattern of each view is tailored to form super Gaussian distribution with minimized crosstalk. What’s more, spatial multiplexing holographic combiner with customized aperture size is adopted for the white balance of virtually displayed full-color 3D scene. In a 32-inch prototype, 16 views form a smooth parallax with a viewing angle of 47°. A high transmission (>75%) over the entire visible spectrum range is achieved. We demonstrated that the displayed virtual 3D scene not only preserved natural motion parallax, but also mixed well with the natural objects. The potential applications of this study include education, communication, product design, advertisement, and head-up display.
Dynamics of carbon nanotube-based mode-locking fiber lasers
Authors: Huang Lin , Zhang Yusheng , Liu Xueming 
Published: June 2020

Abstract
Carbon nanotube (CNT) can work as excellent saturable absorber (SA) due to its advantages of fast recovery, low saturation intensity, polarization insensitivity, deep modulation depth, broad operation bandwidth, outstanding environmental stability, and affordable fabrication. Its successful application as SA has promoted the development of scientific research and practical application of mode-locked fiber lasers. Besides, mode-locked fiber laser constitutes an ideal platform for investigating soliton dynamics which exhibit profound nonlinear optical dynamics and excitation ubiquitous in many fields. Up to now, a variety of soliton dynamics have been observed. Among these researches, CNT-SA is a key component that suppresses the environmental perturbation and optimizes the laser system to reveal the true highly stochastic and non-repetitive unstable phenomena of the initial self-starting lasing process. This review is intended to provide an up-to-date introduction to the development of CNT-SA based ultrafast fiber lasers, with emphasis on recent progress in real-time buildup dynamics of solitons in CNT-SA mode-locked fiber lasers. It is anticipated that study of dynamics of solitons can not only further reveal the physical nature of solitons, but also optimize the performance of ultrafast fiber lasers and eventually expand their applications in different fields.
ENVIRAD – A Database Integration for Environmental Samples Radiological Data
Authors: Gonzalez Sergio de Albuquerque , Silva Tadeu Augusto de Almeida , Conti Claudio de Carvalho , Osvath Iolanda , Ramadan Hussein , Bartocci Jean 
Published: June 2020

With the increasing use of databases for environmental radiological monitoring in soils, food, water and sediments, among others, there is a demand for integrating this kind of information availability, aiming at a data management for greater searchability for the most varied purposes. ENVIRAD is a proposal to integrate these databases, providing researchers with a tool for a more complete analysis of the environment’s study. ENVIRAD, as developed so far, works with the integration of the following databases: MARIS, GLOMARD, GEORAD and SIGLARA databases, enabling queries and demonstrating great potential in the use of data integration for environmental samples.
THE RHIZOMATIC LEARNING FROM A PERSPECTIVE OF POSTSTRUCTURALISM
Authors: Kairiené Aida 
Published: June 2020

Aim.The postmodernism manifested itself in the second half of the 20th century. The branch of postmodernism is poststructuralism - in fact, it was called French poststructuralism, with the dominant philosophy being “68 philosophy” (Marshall, 2004). In that period, alongside influential works such as Derrida “On Grammatology” (1968), M. Foulcalt “The Madness and Civilization” (1967), J. Kristeva “Semiotics” (1969) emerged and Deleuze, Guattari personalities. According to the Eurydice study, 9 out of 10 students in the European Union study English. Students can learn English not only in formal but also in non-formal and informal forms. This enables the development of rhizomatic learning, which origins lie in Deleuze, Guattari (2004) philosophy. Thus, the problem – related question arises: what is the essence of rhizomatic learning from a perspective of poststructuralism? The aim of the study is to review theoretical considerations in order to reveal the essence of rhizomatic learning from a perspective of poststructuralism.
Method.The research method – a scientific literature review. The literature review examines relevant, current, and recent literature (Grant & Booth, 2009). The literature review is based on philosophical and educational insights. The following sources have been selected for the analysis of rhizomatic learning of English: 1) philosophical and educational books that help to reveal the essence of rhizomatic learning; 2) publications and dissertations on the issue of rhizomatic learning, which helped to analyse the essence of rhizomatic learning from a perspective of poststructuralism.
Results. The antecedents of rhizomatic learning are rhizome and other Deleuze Guattari's (2004) concepts as assemblages, becoming, nomad. The rhizomatic learning based on Deleuze Guattari's (2004) term of rhizome, which has neither beginning nor end (Cormier, 2008), providing a dynamic, open, personalized learning network created by learners themselves that meets their perceived and real needs (Lian, Pineda, 2014). The concept of rhizomatic learning has its own meaning, but is closely related to the concepts of Deleuze, Guattari (2004), such as rhizome, assemblage, becoming, nomad, and so on. It should be noted that the rhizomatic learning from poststructuralism perspective develops and manifests itself through various 'moving' Deleuze, Guattari’s (2004) concepts. The consequences of rhizomatic learning show that rhizomatic learning could be applied successfully in educational science as learning foreign languages in various learning forms.
Conclusion. The scientific analysis revealed that rhizomatic learning develops through Deleuze, Guattari concepts, especially through becoming learner and occurs in lifelong learning of English.
SOCIAL NETWORKS AS A SUPPORT IN THE OLD AGE IN SPAIN
Authors: AGUDO PRADO SUSANA , García-Sampedro Marta 
Published: June 2020

Aim. This article presents the results of research whose aim is to establish if social networks are useful tools to promote social relationships and support for the elderly citizens.
Method. One hundred thirty people over the age of 65 participated in the research. For this purpose, the scale “elderly people and social network” (elaborated ad hoc) was applied.
Results and conclusion. The results obtained through descriptive analysis of the gathered data indicate that social networks provide support for elderly people who had already acquired digital competence in the past. The study also reveals that there are personal variables, especially of an educational nature, that determine the acquisition of an active role as generators and producers of digital content (prosumers). In conclusion, it could be said that social networks have a positive influence on the well-being of the elderly and their fight against undesirable loneliness. The more heterogeneous the social network is, the more active the elderly people are.