Nanophotonics最新文献

{"title":"Designing rotational motion of charge densities on plasmonic nanostructures excited by circularly polarized light","authors":"Naoki Ichiji, Takuya Ishida, Ikki Morichika, Daigo Oue, Tetsu Tatsuma, Satoshi Ashihara","doi":"10.1515/nanoph-2024-0433","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0433","url":null,"abstract":"Rotational motion of charges in plasmonic nanostructures plays an important role in transferring angular momentum between light and matter on the nanometer scale. Although sophisticated control of rotational charge motion has been achieved using spatially structured light, its extension to simultaneous excitation of the same charge motion in multiple nanostructures is not straightforward. In this study, we perform model calculations to show that spatially homogeneous circularly polarized (CP) light can excite rotational charge motions with a high degrees of freedom by exploiting the rotational symmetry of the plasmonic structure and that of the plasmon mode. Finite-difference time-domain simulations demonstrate selective excitation of rotational charge motion for both isolated nanoplates and periodic array structures, showing that complex charge rotations can be manipulated by plane CP waves in a wide range of plasmonic structures.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"34 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of temperature on the brightening of neutral and charged dark excitons in WSe2 monolayer","authors":"Łucja Kipczak, Natalia Zawadzka, Dipankar Jana, Igor Antoniazzi, Magdalena Grzeszczyk, Małgorzata Zinkiewicz, Kenji Watanabe, Takashi Taniguchi, Marek Potemski, Clément Faugeras, Adam Babiński, Maciej R. Molas","doi":"10.1515/nanoph-2024-0385","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0385","url":null,"abstract":"Optically dark states play an important role in the electronic and optical properties of monolayers (MLs) of semiconducting transition metal dichalcogenides. The effect of temperature on the in-plane-field activation of the neutral and charged dark excitons is investigated in a WSe<jats:sub>2</jats:sub> ML encapsulated in hexagonal BN flakes. The brightening rates of the neutral dark (<jats:italic>X</jats:italic> <jats:sup>D</jats:sup>) and grey (<jats:italic>X</jats:italic> <jats:sup>G</jats:sup>) excitons and the negative dark trion (<jats:italic>T</jats:italic> <jats:sup>D</jats:sup>) differ substantially at particular temperature. More importantly, they weaken considerably by about 3–4 orders of magnitude with temperature increased from 4.2 K to 100 K. The quenching of the dark-related emissions is accompanied by the two-order-of-magnitude increase in the emissions of their neutral bright counterparts, <jats:italic>i</jats:italic>.<jats:italic>e</jats:italic>. neutral bright exciton (<jats:italic>X</jats:italic> <jats:sup>B</jats:sup>) and spin-singlet (<jats:italic>T</jats:italic> <jats:sup>S</jats:sup>) and spin-triplet (<jats:italic>T</jats:italic> <jats:sup>T</jats:sup>) negative trions, due to the thermal activations of dark states. Furthermore, the energy splittings between the dark <jats:italic>X</jats:italic> <jats:sup>D</jats:sup> and <jats:italic>T</jats:italic> <jats:sup>D</jats:sup> complexes and the corresponding bright <jats:italic>X</jats:italic> <jats:sup>B</jats:sup>, <jats:italic>T</jats:italic> <jats:sup>S</jats:sup>, and <jats:italic>T</jats:italic> <jats:sup>T</jats:sup> ones vary with temperature rises from 4.2 K to 100 K. This is explained in terms of the different exciton–phonon coupling for the bright and dark excitons stemming from their distinct symmetry properties.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"129 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An overview on plasmon-enhanced photoluminescence via metallic nanoantennas","authors":"José Luis Montaño-Priede, Mario Zapata-Herrera, Ruben Esteban, Nerea Zabala, Javier Aizpurua","doi":"10.1515/nanoph-2024-0463","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0463","url":null,"abstract":"In the realm of nanotechnology, the integration of quantum emitters with plasmonic nanostructures has emerged as an innovative pathway for applications in quantum technologies, sensing, and imaging. This research paper provides a comprehensive exploration of the photoluminescence enhancement induced by the interaction between quantum emitters and tailored nanostructure configurations. Four canonical nanoantennas (spheres, rods, disks, and crescents) are systematically investigated theoretically in three distinct configurations (single, gap, and nanoparticle-on-mirror nanoantennas), as a representative selection of the most fundamental and commonly studied structures and arrangements. A detailed analysis reveals that the rod gap nanoantenna configuration achieves the largest photoluminescence enhancement factor, of up to three orders of magnitude. The study presented here provides insights for the strategic design of plasmonic nanoantennas in the visible and near-IR spectral range, offering a roadmap for these structures to meet specific requirements in plasmon-enhanced fluorescence. Key properties such as the excitation rate, the quantum yield, the enhanced emitted power, or the directionality of the emission are thoroughly reviewed. The results of this overview contribute not only to the fundamental understanding of plasmon-enhanced emission of quantum emitters but also set the basis for the development of advanced nanophotonic devices with enhanced functionalities.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"66 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasmon-driven molecular scission","authors":"Hui Wang","doi":"10.1515/nanoph-2024-0417","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0417","url":null,"abstract":"Plasmon-driven photocatalysis offers a unique means of leveraging nanoscale light–matter interactions to convert photon energy into chemical energy in a chemoselective and regioselective manner under mild reaction conditions. Plasmon-driven bond cleavage in molecular adsorbates represents a critical step in virtually all plasmon-mediated photocatalytic reactions and has been identified as the rate-determining step in many cases. This review article summarizes critical insights concerning plasmon-triggered bond-cleaving mechanisms gained through combined experimental and computational efforts over the past decade or so, elaborating on how the plasmon-derived physiochemical effects, metal–adsorbate interactions, and local chemical environments profoundly influence chemoselective bond-cleaving processes in a diverse set of molecular adsorbates ranging from small diatomic molecules to aliphatic and aromatic organic compounds. As demonstrated by several noteworthy examples, insights gained from fundamental mechanistic studies lay a critical knowledge foundation guiding rational design of nanoparticle–adsorbate systems with desired plasmonic molecule-scissoring functions for targeted applications, such as controlled release of molecular cargos, surface coating of solid-state materials, and selective bond activation for polymerization reactions.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"3 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced zero-phonon line emission from an ensemble of W centers in circular and bowtie Bragg grating cavities","authors":"Vijin Kizhake Veetil, Junyeob Song, Pradeep N. Namboodiri, Nikki Ebadollahi, Ashish Chanana, Aaron M. Katzenmeyer, Christian Pederson, Joshua M. Pomeroy, Jeffrey Chiles, Jeffrey Shainline, Kartik Srinivasan, Marcelo Davanco, Matthew Pelton","doi":"10.1515/nanoph-2024-0485","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0485","url":null,"abstract":"Color centers in silicon have recently gained considerable attention as single-photon sources and as spin qubit-photon interfaces. However, one of the major bottlenecks to the application of silicon color centers is their low overall brightness due to a relatively slow emission rate and poor light extraction from silicon. Here, we increase the photon collection efficiency from an ensemble of a particular kind of color center, known as W centers, by embedding them in circular Bragg grating cavities resonant with their zero-phonon-line emission. We observe a ≈5-fold enhancement in the photon collection efficiency (the fraction of photons extracted from the sample and coupled into a single-mode fiber), corresponding to an estimated ≈11-fold enhancement in the photon extraction efficiency (the fraction of photons collected by the first lens above the sample). For these cavities, we observe lifetime reduction by a factor of <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <m:mo>≈</m:mo> <m:mn>1.3</m:mn> </m:math> <jats:tex-math>${approx} 1.3$</jats:tex-math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_nanoph-2024-0485_ineq_001.png\"/> </jats:alternatives> </jats:inline-formula>. For W centers in resonant bowtie-shaped cavities, we observed a ≈3-fold enhancement in the photon collection efficiency, corresponding to a ≈6-fold enhancement in the photon extraction efficiency, and observed a lifetime reduction factor of <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <m:mo>≈</m:mo> <m:mn>1.1</m:mn> </m:math> <jats:tex-math>${approx} 1.1$</jats:tex-math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_nanoph-2024-0485_ineq_002.png\"/> </jats:alternatives> </jats:inline-formula>. The bowtie cavities thus preserve photon collection efficiency and Purcell enhancement comparable to circular cavities while providing the potential for utilizing in-plane excitation methods to develop a compact on-chip light source.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"19 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of NC-LSPR coupled MoS2 phototransistors for high-performance broad-spectrum detection","authors":"Weichao Jiang, Yuheng Deng, Rui Su, Jingping Xu, Lu Liu","doi":"10.1515/nanoph-2024-0371","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0371","url":null,"abstract":"In this work, negative-capacitance (NC) and local surface plasmon resonance (LSPR) coupled MoS<jats:sub>2</jats:sub> phototransistors with a gate stack of HZO/AuNPs/Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/MoS<jats:sub>2</jats:sub> are fabricated, and the impacts of Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> interlayer-thickness (<jats:italic>T</jats:italic> <jats:sub>AlO</jats:sub>) on the LSPR effect, the tensile strain on MoS<jats:sub>2</jats:sub> from the Au nanoparticles (AuNPs), the capacitance matching of the NC effect from Hf<jats:sub>0.5</jats:sub>Zr<jats:sub>0.5</jats:sub>O<jats:sub>2</jats:sub> (HZO) ferroelectric layer and the optoelectrical properties of the relevant devices are investigated. Through optimizing <jats:italic>T</jats:italic> <jats:sub>AlO</jats:sub>, excellent optoelectrical properties of phototransistors with a <jats:italic>T</jats:italic> <jats:sub>AlO</jats:sub> of 3 nm are achieved: a subthreshold swing (<jats:italic>SS</jats:italic>) of 25.76 mV/dec and ultrahigh detectivity of over 10<jats:sup>14</jats:sup> Jones under 740 nm illumination. This is primarily because the NC-LSPR coupled structure can achieve an ultra-low <jats:italic>SS</jats:italic> through capacitance matching and a good interface passivation through optimizing Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> interlayer to maintain effective LSPR and strain effects cross the MoS<jats:sub>2</jats:sub> to enhance optical absorption and detection range. This work provides a comprehensive analysis on effective distance range of the non-direct-contacted LSPR effect and its combination with capacitance matching of NC effect, culminating in an optimized NC-LSPR coupled MoS<jats:sub>2</jats:sub> phototransistor with a good consistency across an array of 30 devices, and offering a viable solution for the preparation of large-area, high-performance and broad-spectrum response 2D phototransistor array.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"54 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-compact thin-film-lithium-niobate photonic chip for dispersion compensation","authors":"Shujun Liu, Ruitao Ma, Weihan Wang, Zejie Yu, Daoxin Dai","doi":"10.1515/nanoph-2024-0312","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0312","url":null,"abstract":"Thin-film-lithium-niobate (TFLN) photonics has attracted intensive attention and become very popular in recent years. Here, an ultra-compact TFLN on-chip dispersion compensator is proposed and realized to provide a promising solution for dispersion control. The proposed dispersion compensator is composed of chirped multimode waveguide gratings (CMWGs) arranged in zigzag-cascade, enabling high footprint compactness and scalability. Particularly, these CMWGs are circulator-free and very convenient for cascading, owing to the TE<jats:sub>0</jats:sub>–TE<jats:sub>1</jats:sub> mode conversion and the assistance of the TE<jats:sub>0</jats:sub>–TE<jats:sub>1</jats:sub> mode (de)multiplexer. The present configuration with CMWGs in zigzag-cascade also overcomes the drawback of being unable to use waveguide spirals for large-range time delay and dispersion control due to the TFLN’s anisotropy. In addition, positive/negative dispersion control is realized by appropriately choosing the input port of the CMWGs. In the experiment, 2-mm-long CMWGs are used to provide a dispersion value of about +1.5 ps/nm and −1.2 ps/nm over a 21-nm-wide bandwidth, and there are up to 32 CMWGs in cascade demonstrated experimentally, showing a maximal dispersion of 49.2 ps/nm and −39.3 ps/nm. The corresponding average propagation loss is as low as 0.47 dB/cm, and the fabricated chip with 32 CMWGs in zigzag-cascade has a footprint as compact as 0.16 × 4.65 mm<jats:sup>2</jats:sup>. Finally, the present on-chip dispersion compensator is used successfully to compensate for the dispersion originating from a 5-km-long singlemode fiber (SMF) and high-quality eye-diagrams are achieved for the recovered 40 Gbps OOK signals, showing great potential for optical systems such as high-speed interconnects in datacenters.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"95 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unique features of plasmonic absorption in ultrafine metal nanoparticles: unity and rivalry of volumetric compression and spill-out effect","authors":"Daniil Khrennikov, Victor Labuntsov, Konstantin Ladutenko, Ivan Terekhov, Andrey Bogdanov, Hans Ågren, Sergey Karpov","doi":"10.1515/nanoph-2024-0475","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0475","url":null,"abstract":"We present a solution to a longstanding challenge in nanoplasmonics and colloid chemistry: the anomalous optical absorption of noble metal nanoparticles in the ultrafine size range of 2.5–10 nm, characterized by a rapid long-wavelength shift in plasmon resonance as the particle size increases. Our investigation delves into the impact of alterations in electron density along the radial direction of nanoparticles and the resulting variations in dielectric constants on the spectral positioning of the plasmon resonance. We explore the interplay of the spill-out effect, volumetric compression, and their combined impact in different experimental conditions on electron density variation within the particle volume and its blurring at the particle boundary. The latter effectively forms a surface layer with altered dielectric constants and a size-independent extent. As particle size decreases, the influence of the surface layer becomes more pronounced, especially when its extent is comparable to the particle radius. These findings are specific to ultrafine plasmonic nanoparticles and highlight their unique properties.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"5 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142580388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Double-helix singularity and vortex–antivortex annihilation in space-time helical pulses","authors":"Shuai Shi, Ren Wang, Minhui Xiong, Qinyu Zhou, Bing-Zhong Wang, Yijie Shen","doi":"10.1515/nanoph-2024-0480","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0480","url":null,"abstract":"Topological structures reveal the hidden secrets and beauty in nature, such as the double helix in DNA, whilst, the manipulation of which in physical fields, especially in ultrafast structured light, draw booming attention. Here we introduce a new family of spatiotemporal light fields, i.e. helical pulses, carrying sophisticated double-helix singularities in its electromagnetic topological structures. The helical pulses were solved from Maxwell’s equation as chiral extensions of toroidal light pulses but with controlled angular momentum dependence. We unveil that the double helix singularities can maintain their topological invariance during propagation and the field exhibits paired generation and annihilation of vortices and antivortices in ultrafast space-time, so as to be potential information carriers beating previous conventional vortex structured light.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"13 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silicon rich nitride: a platform for controllable structural colors","authors":"Oren Goldberg, Noa Mazurski, Uriel Levy","doi":"10.1515/nanoph-2024-0454","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0454","url":null,"abstract":"High refractive index dielectric materials like silicon rich nitride (SRN) are critical for constructing advanced dielectric metasurfaces but are limited by transparency and complementary metal oxide semiconductor (CMOS) process compatibility. SRN’s refractive index can be adjusted by varying the silicon to nitride ratio, although this increases absorption, particularly in the blue spectrum. Dielectric metasurfaces, which utilize the material’s high dielectric constant and nano-resonator geometry, experience loss amplification due to resonance, affecting light reflection, light transmission, and quality factor. This study explores the impact of varying the silicon ratio on structural color applications in metasurfaces, using metrics such as gamut coverage, saturation, and reflection amplitude. We found that a higher SRN ratio enhances these metrics, making it ideal for producing vivid structural colors. Our results show that SRN can produce a color spectrum covering up to 166 % of the sRGB space and a resolution of 38,000 dots per inch. Fabricated samples vividly displayed a parrot, a flower, and a rainbow, illustrating SRN’s potential for high-resolution applications. We also show that SRN can provide a better CIE diagram coverage than other popular metasurfaces materials. These findings highlight the advantages of SRN for photonic devices, suggesting pathways for further material and application development.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"7 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}