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Ou JY, Chen WS, Chen MJ, Zhao LZ, Li LH, Peng L, Liang L, Shi YL. [Effects of ppk1 deletion on the drug susceptibility of uropathogenic Escherichia coli producing ESBLs]. Zhonghua Yu Fang Yi Xue Za Zhi 2023; 57:1238-1245. [PMID: 37574318 DOI: 10.3760/cma.j.cn112150-20220906-00876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
To investigate the effect and the mechanism of ppk1 gene deletion on the drug susceptibility of uropathogenic Escherichia coli producing extended-spectrum beta-lactamases (ESBLs-UPEC). The study was an experimental study. From March to April 2021, a strain of ESBLs-UPEC (genotype was TEM combined with CTX-M-14) named as UE210113, was isolated from urine sample of the patient with urinary tract infection in the Laboratory Department of Guangzhou Eighth People's Hospital, meanwhile its ppk1 gene knock-out strain Δpk1 and complemented strain Δpk1-C were constructed by suicide plasmid homologous recombination technique, which was used to study the effect of ppk1 gene on ESBLs-UPEC drug sensitivity and its mechanism. The drug susceptibility of UE210113, Δpk1, and Δpk1-C were measured by Vitek2 Compact System and broth microdilution method. The quantitative expression of ESBLs, outer membrane protein and multidrug efflux systems encoding genes of UE210113, Δpk1 and Δpk1-C were performed by using qRT-PCR analysis. By using two independent sample Mann-Whitney U test, the drug susceptibility results showed that, compared with UE210113 strain, the sensitivities of Δpk1 to ceftazidime, cefepime, tobramycin, minocycline and cotrimoxazole were enhanced (Z=-2.121,P<0.05;Z=-2.236,P<0.05;Z=-2.236,P<0.05;Z=-2.121,P<0.05), and the drug susceptibility of Δpk1-C restored to the same as which of UE210113 (Z=0,P>0.05). The expression levels of ESBLs-enconding genes blaTEM and blaCTX-M-14 in Δpk1 were significantly down-regulated compared with UE210113, but the expression was not restored in Δpk1-C. The expression of outer membrane protein gene omp F in Δpk1 was significantly up-regulated, while the expression of omp A and omp C were down-regulated. The results showed that the expression of multidrug efflux systems encoding genes tol C, mdt A and mdtG were down-regulated in Δpk1 compared with UE210113. The expression of all of the outer membrane protein genes and the multidrug efflux systems genes were restored in Δpk1-C. In conclusion,the lost of ppk1 gene can affect the expression of the outer membrane protein and multidrug efflux systems encoding genes of ESBLs-UPEC, which increase the sensitivity of ESBLs-UPEC to various drugs.
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Affiliation(s)
- J Y Ou
- Department of Clinical Laboratory, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510440 China
| | - W S Chen
- Department of Clinical Laboratory, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510440 China
| | - M J Chen
- Department of Clinical Laboratory, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510440 China
| | - L Z Zhao
- Department of Clinical Laboratory, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510440 China
| | - L H Li
- Infectious Department, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510440, China
| | - L Peng
- Department of Clinical Laboratory, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou 510700, China
| | - L Liang
- The KingMed College of Laboratory Medicine,Guangzhou Medical University, Guangzhou 511436, China
| | - Y L Shi
- Department of Clinical Laboratory, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510440 China
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Liu T, Chi CH, Ou JY, Xu J, Chan EA, MacDonald KF, Zheludev NI. Picophotonic localization metrology beyond thermal fluctuations. Nat Mater 2023; 22:844-847. [PMID: 37169973 PMCID: PMC10691967 DOI: 10.1038/s41563-023-01543-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 03/28/2023] [Indexed: 05/13/2023]
Abstract
Despite recent tremendous progress in optical imaging and metrology1-6, there remains a substantial resolution gap between atomic-scale transmission electron microscopy and optical techniques. Is optical imaging and metrology of nanostructures exhibiting Brownian motion possible with such resolution, beyond thermal fluctuations? Here we report on an experiment in which the average position of a nanowire with a thermal oscillation amplitude of ∼150 pm is resolved in single-shot measurements with subatomic precision of 92 pm, using light at a wavelength of λ = 488 nm, providing an example of such sub-Brownian metrology with ∼λ/5,300 precision. To localize the nanowire, we employ a deep-learning analysis of the scattering of topologically structured light, which is highly sensitive to the nanowire's position. This non-invasive metrology with absolute errors down to a fraction of the typical size of an atom, opens a range of opportunities to study picometre-scale phenomena with light.
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Affiliation(s)
- Tongjun Liu
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, UK
| | - Cheng-Hung Chi
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, UK
- School of Physics and Astronomy, University of Southampton, Southampton, UK
| | - Jie Xu
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, UK
| | - Eng Aik Chan
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore, Singapore
| | - Kevin F MacDonald
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, UK
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, UK.
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore, Singapore.
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3
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Li P, Wang S, Mashanovich GZ, Ou JY, Yan J. Enhanced stimulated Brillouin scattering in the unsuspended silicon waveguide assisted with genetic algorithms. Opt Express 2023; 31:16162-16177. [PMID: 37157701 DOI: 10.1364/oe.488009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Stimulated Brillouin scattering (SBS), originating from the coupling between optical and acoustic waves, has been widely applied in many fields. Silicon is the most used and important material in micro-electromechanical systems (MEMS) and integrated photonic circuits. However, strong acoustic-optic interaction in silicon requires mechanical release of the silicon core waveguide to avoid acoustic energy leakage into the substrate. This will not only reduce the mechanical stability and thermal conduction, but also increase the difficulties for fabrication and large-area device integration. In this paper, we propose a silicon-aluminium nitride(AlN)-sapphire platform for realizing large SBS gain without suspending the waveguide. AlN is used as a buffer layer to reduce the phonon leakage. This platform can be fabricated via the wafer bonding between silicon and commercial AlN-sapphire wafer. We adopt a full-vectorial model to simulate the SBS gain. Both the material loss and the anchor loss of the silicon are considered. We also apply the genetic algorithm to optimize the waveguide structure. By limiting the maximum etching step number to two, we obtain a simple structure to achieve the SBS gain of 2462 W-1m-1 for forward SBS, which is 8 times larger than the recently reported result in unsuspended silicon waveguide. Our platform can enable Brillouin-related phenomena in centimetre-scale waveguides. Our findings could pave the way toward large-area unreleased opto-mechanics on silicon.
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Chen W, Gao Y, Li Y, Yan Y, Ou JY, Ma W, Zhu J. Broadband Solar Metamaterial Absorbers Empowered by Transformer-Based Deep Learning. Adv Sci (Weinh) 2023; 10:e2206718. [PMID: 36852630 PMCID: PMC10161039 DOI: 10.1002/advs.202206718] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/03/2023] [Indexed: 05/06/2023]
Abstract
The research of metamaterial shows great potential in the field of solar energy harvesting. In the past decade, the design of broadband solar metamaterial absorber (SMA) has attracted a surge of interest. The conventional design typically requires brute-force optimizations with a huge sampling space of structure parameters. Very recently, deep learning (DL) has provided a promising way in metamaterial design, but its application on SMA development is barely reported due to the complicated features of broadband spectrum. Here, this work develops the DL model based on metamaterial spectrum transformer (MST) for the powerful design of high-performance SMAs. The MST divides the optical spectrum of metamaterial into N patches, which overcomes the severe problem of overfitting in traditional DL and boosts the learning capability significantly. A flexible design tool based on free customer definition is developed to facilitate the real-time on-demand design of metamaterials with various optical functions. The scheme is applied to the design and fabrication of SMAs with graded-refractive-index nanostructures. They demonstrate the high average absorptance of 94% in a broad solar spectrum and exhibit exceptional advantages over many state-of-the-art counterparts. The outdoor testing implies the high-efficiency energy collection of about 1061 kW h m-2 from solar radiation annually. This work paves a way for the rapid smart design of SMA, and will also provide a real-time developing tool for many other metamaterials and metadevices.
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Affiliation(s)
- Wei Chen
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, Fujian, 361005, P. R. China
- Shenzhen Research Institute of Xiamen University, Shenzhen, Guangdong, 518057, China
| | - Yuan Gao
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, Fujian, 361005, P. R. China
| | - Yuyang Li
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, Fujian, 361005, P. R. China
| | - Yiming Yan
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, Fujian, 361005, P. R. China
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, UK, SO17 1BJ
| | - Wenzhuang Ma
- State Key Laboratory of Electronic Thin Films and Integrated Devices, National Engineering Research Center of Electromagnetic Radiation Control Materials, Key Laboratory of Multi-spectral Absorbing Materials and Structures of Ministry of Education, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054, P. R. China
| | - Jinfeng Zhu
- Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen, Fujian, 361005, P. R. China
- Shenzhen Research Institute of Xiamen University, Shenzhen, Guangdong, 518057, China
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Papas D, Ou JY, Plum E, Zheludev NI. Microwatt Volatile Optical Bistability via Nanomechanical Nonlinearity. Adv Sci (Weinh) 2023:e2300042. [PMID: 37186378 DOI: 10.1002/advs.202300042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/30/2023] [Indexed: 05/17/2023]
Abstract
Metastable optically controlled devices (optical flip-flops) are needed in data storage, signal processing, and displays. Although nonvolatile memory relying on phase transitions in chalcogenide glasses has been widely used for optical data storage, beyond that, weak optical nonlinearities have hindered the development of low-power bistable devices. This work reports a new type of volatile optical bistability in a hybrid nano-optomechanical device, comprising a pair of anchored nanowires decorated with plasmonic metamolecules. The nonlinearity and bistability reside in the mechanical properties of the acoustically driven nanowires and are transduced to the optical response by reconfiguring the plasmonic metamolecules. The device can be switched between bistable optical states with microwatts of optical power and its volatile memory can be erased by removing the acoustic signal. The demonstration of hybrid nano-optomechanical bistability opens new opportunities to develop low-power optical bistable devices.
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Affiliation(s)
- Dimitrios Papas
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - Eric Plum
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
- Centre for Disruptive Photonic Technologies, SPMS, TPI, Nanyang Technological University, Singapore, 637371, Singapore
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Lan G, Wang Y, Ou JY. Optimization of metamaterials and metamaterial-microcavity based on deep neural networks. Nanoscale Adv 2022; 4:5137-5143. [PMID: 36504733 PMCID: PMC9680957 DOI: 10.1039/d2na00592a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/27/2022] [Indexed: 05/25/2023]
Abstract
Computational inverse-design and forward prediction approaches provide promising pathways for on-demand nanophotonics. Here, we use a deep-learning method to optimize the design of split-ring metamaterials and metamaterial-microcavities. Once the deep neural network is trained, it can predict the optical response of the split-ring metamaterial in a second which is much faster than conventional simulation methods. The pretrained neural network can also be used for the inverse design of split-ring metamaterials and metamaterial-microcavities. We use this method for the design of the metamaterial-microcavity with the absorptance peak at 1310 nm. Experimental results verified that the deep-learning method is a fast, robust, and accurate method for designing metamaterials with complex nanostructures.
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Affiliation(s)
- Guoqiang Lan
- School of Electronic Engineering, Heilongjiang University No. 74 Xuefu Road Harbin 150080 China
- Heilongjiang Provincial Key Laboratory of Micro-nano Sensitive Devices and Systems, Heilongjiang University Harbin 150080 China
| | - Yu Wang
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield Southampton SO17 1BJ UK
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7
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Liu T, Ou JY, Papasimakis N, MacDonald KF, Gusev VE, Zheludev NI. Ballistic dynamics of flexural thermal movements in a nanomembrane revealed with subatomic resolution. Sci Adv 2022; 8:eabn8007. [PMID: 35984884 PMCID: PMC9390981 DOI: 10.1126/sciadv.abn8007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/07/2022] [Indexed: 05/26/2023]
Abstract
Flexural oscillations of freestanding films, nanomembranes, and nanowires are attracting growing attention for their importance to the fundamental physical and optical properties and device applications of two-dimensional and nanostructured (meta)materials. Here, we report on the observation of short-time scale ballistic motion in the flexural mode of a nanomembrane cantilever, driven by thermal fluctuation of flexural phonons, including measurements of ballistic velocities and displacements performed with subatomic resolution, using a free electron edge-scattering technique. Within intervals <10 μs, the membrane moves ballistically at a constant velocity, typically ~300 μm/s, while Brownian-like dynamics emerge for longer observation periods. Access to the ballistic regime provides verification of the equipartition theorem and Maxwell-Boltzmann statistics for flexural modes and can be used in fast thermometry and mass sensing during atomic absorption/desorption processes on the membrane.
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Affiliation(s)
- Tongjun Liu
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Nikitas Papasimakis
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Kevin F. MacDonald
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
| | - Vitalyi E. Gusev
- Laboratoire d’Acoustique de l’Université du Mans (LAUM), Institut d’Acoustique-Graduate School (IA-GS), CNRS, Le Mans Université, 72085 Le Mans, France
| | - Nikolay I. Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton Highfield, Southampton SO17 1BJ, UK
- Centre for Disruptive Photonic Technologies and The Photonics Institute, SPMS, Nanyang Technological University, 637371, Singapore
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8
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Li P, Ou JY, Mashanovich GZ, Yan J. Tailorable stimulated Brillouin scattering in a partially suspended aluminium nitride waveguide in the visible range. Opt Express 2022; 30:27092-27108. [PMID: 36236887 DOI: 10.1364/oe.462356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/25/2022] [Indexed: 06/16/2023]
Abstract
Stimulated Brillouin scattering (SBS) has been widely applied in narrow line-width laser, microwave filters, optical gyroscopes, and other fields. However, most research is limited within near-infrared to mid-infrared range. This is due to the limited transparent window in most materials, such as silicon and germanium. Aluminium nitride (AlN) is a novel III-V material with a wide transparent window from 200 nm and an appropriate refractive index to confine the light. In this paper, we first validate the full-vectorial formalism to calculate SBS gain based on the measured results from a silicon platform. Compared to previous research, our model achieves higher accuracy in terms of frequency, Q factor, as well as Brillouin gain coefficient without modifying the waveguide width. It also reveals the importance of matching rotation matrix and crystalline coordinate system. Then, we investigate the SBS in a partially suspended AlN waveguide at 450 nm based on the validated method. It shows a wide tunability in frequency from 16 GHz to 32 GHz for forward SBS and a range from 42 GHz to 49 GHz for backward SBS. We numerically obtain the value of Brillouin gain of 1311 W-1m-1 when Q factor is dominated by anchor loss for forward SBS of transverse electric mode. We also find out that in the case for forward SBS of transverse-magnetic mode, anchor loss could be greatly suppressed when the node point of the selected acoustic mode matches with the position of pillar anchor. Our findings, to the best of our knowledge, pave a new way to obtain Brillouin-related applications in integrated photonic circuit within the visible range.
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Wang Q, Zhang L, Cai X, Cencillo-Abad P, Ou JY. Tunable angle-selective optical transparency induced by photonic topological transition in Dirac semimetals-based hyperbolic metamaterials. Opt Express 2022; 30:23102-23114. [PMID: 36224997 DOI: 10.1364/oe.458584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/26/2022] [Indexed: 06/16/2023]
Abstract
The tunable angle-selective transparency of hyperbolic metamaterials consisting of various multilayers of Dirac semimetal and dielectric materials are theoretically and numerically studied in the terahertz range. Three stack configurations are considered: alternating, sandwiched, and disordered. It is found that the proposed structures exhibit strong optical angular selectivity induced by photonic topological transition for transverse magnetic waves. Interestingly, the topological transition frequency can be flexibly modulated by changing the Fermi energy, temperature, and the releasing time of the Dirac semimetal, as well as the thickness ratio of the dielectric and semimetal layers. It is also noticed that the angular optical transparency properties are independent of the order of the proposed structure even in alternating/disordered/random configurations if the total thickness ratio of the semimetal to dielectric are the same, which makes the properties particularly easy to realize experimentally. The proposed hyperbolic metamaterial structures present a promising opportunity for wavefront engineering, offering crucial properties for applications in private screens, optical detectors, and light manipulation.
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Liu T, Ou JY, Plum E, MacDonald KF, Zheludev NI. Visualization of Subatomic Movements in Nanostructures. Nano Lett 2021; 21:7746-7752. [PMID: 34469159 DOI: 10.1021/acs.nanolett.1c02644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Electron microscopy, scanning probe, and optical super-resolution imaging techniques with nanometric resolution are now routinely available but cannot capture the characteristically fast (MHz-GHz frequency) movements of micro-/nano-objects. Meanwhile, optical interferometric techniques can detect high-frequency picometric displacements but only with diffraction-limited lateral resolution. Here, we introduce a motion visualization technique, based on the spectrally resolved detection of secondary electron emission from moving objects, that combines picometric displacement sensitivity with the nanometric spatial (positional/imaging) resolution of electron microscopy. The sensitivity of the technique is quantitatively validated against the thermodynamically defined amplitude of a nanocantilever's Brownian motion. It is further demonstrated in visualizing externally driven modes of cantilever, nanomechanical photonic metamaterial, and MEMS device structures. With a noise floor reaching ∼1 pm/Hz1/2, it can provide for the study of oscillatory movements with subatomic amplitudes, presenting new opportunities for the interrogation of motion in functional structures across the materials, bio- and nanosciences.
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Affiliation(s)
- Tongjun Liu
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Eric Plum
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Kevin F MacDonald
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, U.K
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore 637378, Singapore
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Li H, Ou JY, Fedotov VA, Papasimakis N. Decay rate enhancement of diamond NV-centers on diamond thin films. Opt Express 2021; 29:25626-25631. [PMID: 34614889 DOI: 10.1364/oe.425706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate experimentally two-fold enhancement of the decay rate of NV° centers on diamond/Si substrate as opposed to a bare Si substrate. We link the decay enhancement to the interplay between the excitation of substrate modes and the presence of non-radiative decay channels. We show that the radiative decay rate can vary by up to 90% depending on the thickness of the diamond film.
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12
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Ajia IA, Ou JY, Dinsdale NJ, Singh HJ, Chen-Sverre T, Liu T, Zheludev NI, Muskens OL. Gigahertz Nano-Optomechanical Resonances in a Dielectric SiC-Membrane Metasurface Array. Nano Lett 2021; 21:4563-4569. [PMID: 34015218 DOI: 10.1021/acs.nanolett.1c00205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Optically and vibrationally resonant nanophotonic devices are of particular importance for their ability to enhance optomechanical interactions, with applications in nanometrology, sensing, nano-optical control of light, and optomechanics. Here, the optically resonant excitation and detection of gigahertz vibrational modes are demonstrated in a nanoscale metasurface array fabricated on a suspended SiC membrane. With the design of the main optical and vibrational modes to be those of the individual metamolecules, resonant excitation and detection are achieved by making use of direct mechanisms for optomechanical coupling. Ultrafast optical pump-probe studies reveal a multimodal gigahertz vibrational response corresponding to the mechanical modes of the suspended nanoresonators. Wavelength and polarization dependent studies reveal that the excitation and detection of vibrations takes place through the metasurface optical modes. The dielectric metasurface pushes the modulation speed of optomechanical structures closer to their theoretical limits and presents a potential for compact and easily fabricable optical components for photonic applications.
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Affiliation(s)
- Idris A Ajia
- Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, SO17 1BJ, Southampton, United Kingdom
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Nicholas J Dinsdale
- Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, SO17 1BJ, Southampton, United Kingdom
| | - H Johnson Singh
- Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, SO17 1BJ, Southampton, United Kingdom
| | - Theo Chen-Sverre
- Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, SO17 1BJ, Southampton, United Kingdom
| | - Tongjun Liu
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore 637378, Singapore
| | - Otto L Muskens
- Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, SO17 1BJ, Southampton, United Kingdom
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Liu T, Ou JY, MacDonald KF, Zheludev NI. Detection of sub-atomic movement in nanostructures. Nanoscale Adv 2021; 3:2213-2216. [PMID: 36133771 PMCID: PMC9419005 DOI: 10.1039/d0na01068e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/08/2021] [Indexed: 06/16/2023]
Abstract
Nanoscale objects move fast and oscillate billions of times per second. Such movements occur naturally in the form of thermal (Brownian) motion while stimulated movements underpin the functionality of nano-mechanical sensors and active nano-(electro/opto) mechanical devices. Here we introduce a methodology for detecting such movements, based on the spectral analysis of secondary electron emission from moving nanostructures, that is sensitive to displacements of sub-atomic amplitude. We demonstrate the detection of nanowire Brownian oscillations of ∼10 pm amplitude and hyperspectral mapping of stimulated oscillations of setae on the body of a common flea. The technique opens a range of opportunities for the study of dynamic processes in materials science, nanotechnology and biology.
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Affiliation(s)
- Tongjun Liu
- Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton SO17 1BJ UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton SO17 1BJ UK
| | - Kevin F MacDonald
- Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton SO17 1BJ UK
| | - Nikolay I Zheludev
- Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton SO17 1BJ UK
- Centre for Disruptive Photonic Technologies & the Photonics Institute, Nanyanag Technological University 637371 Singapore
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14
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Zhu J, Zhang L, Jiang S, Ou JY, Liu QH. Selective light trapping of plasmonic stack metamaterials by circuit design. Nanoscale 2020; 12:2057-2062. [PMID: 31912853 DOI: 10.1039/c9nr07937h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Plasmonic metamaterials have wide applications in light trapping and manipulation. However, most of their design typically rely on solving Maxwell's equations via computational electromagnetics, which is time-consuming and limits design flexibility. Here, we combined the transmission line circuit theory with full wave simulation to design plasmonic stack metamaterials in the near-infrared range. By virtue of the simplicity and high efficiency of circuit theory, we designed various light trapping functions by using plasmonic stack metamaterials, including comb filtering, short pass, long pass, band pass and band stop. Our study reveals the field-circuit relationship for the light-matter interaction of nanostructure stacks and provides a powerful method for the quick design of functional plasmonic metamaterials.
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Affiliation(s)
- Jinfeng Zhu
- Institute of Electromagnetics and Acoustics, and Fujian Provincial Key Laboratory of Electromagnetic Wave Science and Detection Technology, Xiamen University, Xiamen 361005, China.
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15
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Abstract
We demonstrate experimentally nonvolatile, all-optical control of graphene's charge transport properties by virtue of an Fe:LiNbO3 photoconductive substrate. The substrate can register and sustain photoinduced charge distributions which modify locally the electrostatic environment of the graphene monolayer and allow spatial control of graphene resistivity. We present light-induced changes of graphene sheet resistivity as high as ∼370 Ω/sq (∼2.6-fold increase) under spatially nonuniform light illumination. The light-induced modifications in the sheet resistivity are stable at room temperature but can be reversed by uniform illumination or thermal annealing (100 °C for 4 h), thus restoring graphene's electrical properties to their initial, preillumination values. The process can be subsequently repeated by further spatially nonuniform illumination.
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Affiliation(s)
- Jon Gorecki
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
| | | | - Jun-Yu Ou
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
| | - Sakellaris Mailis
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
| | - Nikitas Papasimakis
- Optoelectronics Research Centre , University of Southampton , Southampton SO17 1BJ , U.K
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16
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Wang R, Wang BZ, Ding X, Ou JY. Publisher Correction: Planar array with bidirectional elements for tunnel environments. Sci Rep 2018; 8:9234. [PMID: 29899354 PMCID: PMC5998067 DOI: 10.1038/s41598-018-27403-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ren Wang
- Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Bing-Zhong Wang
- Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China.
| | - Xiao Ding
- Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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17
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Cencillo-Abad P, Ou JY, Plum E, Zheludev NI. Electro-mechanical light modulator based on controlling the interaction of light with a metasurface. Sci Rep 2017; 7:5405. [PMID: 28710432 PMCID: PMC5511214 DOI: 10.1038/s41598-017-05906-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/05/2017] [Indexed: 11/30/2022] Open
Abstract
We demonstrate a reflective light modulator, a dynamic Salisbury screen where modulation of light is achieved by moving a thin metamaterial absorber to control its interaction with the standing wave formed by the incident wave and its reflection on a mirror. Electrostatic actuation of the plasmonic metamaterial absorber’s position leads to a dynamic change of the Salisbury screen’s spectral response and 50% modulation of the reflected light intensity in the near infrared part of the spectrum. The proposed approach can also be used with other metasurfaces to control the changes they impose on the polarization, intensity, phase, spectrum and directional distribution of reflected light.
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Affiliation(s)
- Pablo Cencillo-Abad
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - Eric Plum
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.,Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences and The Photonics Institute, Nanyang Technological University, Singapore, 637371, Singapore
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18
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Valente J, Ou JY, Plum E, Youngs IJ, Zheludev NI. Correction: Corrigendum: A magneto-electro-optical effect in a plasmonic nanowire material. Nat Commun 2017; 8:14497. [PMID: 28169301 PMCID: PMC5309707 DOI: 10.1038/ncomms14497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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19
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Abstract
While metamaterials offer engineered static optical properties, future artificial media with dynamic random-access control over shape and position of meta-molecules will provide arbitrary control of light propagation. The simplest example of such a reconfigurable metamaterial is a nanowire grid metasurface with subwavelength wire spacing. Recently we demonstrated computationally that such a metadevice with individually controlled wire positions could be used as dynamic diffraction grating, beam steering module and tunable focusing element. Here we report on the nanomembrane realization of such a nanowire grid metasurface constructed from individually addressable plasmonic chevron nanowires with a 230 nm × 100 nm cross-section, which consist of gold and silicon nitride. The active structure of the metadevice consists of 15 nanowires each 18 μm long and is fabricated by a combination of electron beam lithography and ion beam milling. It is packaged as a microchip device where the nanowires can be individually actuated by control currents via differential thermal expansion.
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Affiliation(s)
- Pablo Cencillo-Abad
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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20
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Ou JY, Plum E, Zhang J, Zheludev NI. Giant Nonlinearity of an Optically Reconfigurable Plasmonic Metamaterial. Adv Mater 2016; 28:729-33. [PMID: 26619205 DOI: 10.1002/adma.201504467] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/01/2015] [Indexed: 05/27/2023]
Abstract
Metamaterial nanostructures actuated by light give rise to a large optical nonlinearity. Plasmonic metamolecules on a flexible support structure cut from a dielectric membrane of nanoscale thickness are rearranged by optical illumination. This changes the optical properties of the strongly coupled plasmonic structure and therefore results in modulation of light with light.
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Affiliation(s)
- Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
| | - Eric Plum
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
| | - Jianfa Zhang
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
- College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha, 410073, China
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, 637378, Singapore
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21
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Valente J, Ou JY, Plum E, Youngs IJ, Zheludev NI. A magneto-electro-optical effect in a plasmonic nanowire material. Nat Commun 2015; 6:7021. [PMID: 25906761 PMCID: PMC4421854 DOI: 10.1038/ncomms8021] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 03/25/2015] [Indexed: 11/09/2022] Open
Abstract
Electro- and magneto-optical phenomena play key roles in photonic technology enabling light modulators, optical data storage, sensors and numerous spectroscopic techniques. Optical effects, linear and quadratic in external electric and magnetic field are widely known and comprehensively studied. However, optical phenomena that depend on the simultaneous application of external electric and magnetic fields in conventional media are barely detectable and technologically insignificant. Here we report that a large reciprocal magneto-electro-optical effect can be observed in metamaterials. In an artificial chevron nanowire structure fabricated on an elastic nano-membrane, the Lorentz force drives reversible transmission changes on application of a fraction of a volt when the structure is placed in a fraction-of-tesla magnetic field. We show that magneto-electro-optical modulation can be driven to hundreds of thousands of cycles per second promising applications in magneto-electro-optical modulators and field sensors at nano-tesla levels. Metamaterials can be engineered to provide electric and magnetic responses that cannot be achieved in natural media. Here, the authors present a metamaterial based on plasmonic chevron nanowires that it exhibits a large reciprocal magneto-electro-optical effect driven by the Lorentz force.
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Affiliation(s)
- João Valente
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Eric Plum
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Ian J Youngs
- Physical Sciences Department, DSTL, Salisbury SP4 0JQ, UK
| | - Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, UK.,The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378, Singapore
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22
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Huang CC, Al-Saab F, Wang Y, Ou JY, Walker JC, Wang S, Gholipour B, Simpson RE, Hewak DW. Scalable high-mobility MoS2 thin films fabricated by an atmospheric pressure chemical vapor deposition process at ambient temperature. Nanoscale 2014; 6:12792-7. [PMID: 25226424 DOI: 10.1039/c4nr04228j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Nano-scale MoS2 thin films are successfully deposited on a variety of substrates by atmospheric pressure chemical vapor deposition (APCVD) at ambient temperature, followed by a two-step annealing process. These annealed MoS2 thin films are characterized with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), micro-Raman, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-VIS-NIR spectrometry, photoluminescence (PL) and Hall Effect measurement. Key optical and electronic properties of APCVD grown MoS2 thin films are determined. This APCVD process is scalable and can be easily incorporated with conventional lithography as the deposition is taking place at room temperature. We also find that the substrate material plays a significant role in the crystalline structure formation during the annealing process and single crystalline MoS2 thin films can be achieved by using both c-plane ZnO and c-plane sapphire substrates. These APCVD grown nano-scale MoS2 thin films show great promise for nanoelectronic and optoelectronic applications.
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Affiliation(s)
- Chung-Che Huang
- Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK.
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23
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Ou JY, Plum E, Zhang J, Zheludev NI. An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared. Nat Nanotechnol 2013; 8:252-255. [PMID: 23503091 DOI: 10.1038/nnano.2013.25] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 01/31/2013] [Indexed: 05/27/2023]
Abstract
Current efforts in metamaterials research focus on attaining dynamic functionalities such as tunability, switching and modulation of electromagnetic waves. To this end, various approaches have emerged, including embedded varactors, phase-change media, the use of liquid crystals, electrical modulation with graphene and superconductors, and carrier injection or depletion in semiconductor substrates. However, tuning, switching and modulating metamaterial properties in the visible and near-infrared range remain major technological challenges: indeed, the existing microelectromechanical solutions used for the sub-terahertz and terahertz regimes cannot be shrunk by two to three orders of magnitude to enter the optical spectral range. Here, we develop a new type of metamaterial operating in the optical part of the spectrum that is three orders of magnitude faster than previously reported electrically reconfigurable metamaterials. The metamaterial is actuated by electrostatic forces arising from the application of only a few volts to its nanoscale building blocks-the plasmonic metamolecules-that are supported by pairs of parallel strings cut from a flexible silicon nitride membrane of nanoscale thickness. These strings, of picogram mass, can be driven synchronously to megahertz frequencies to electromechanically reconfigure the metamolecules and dramatically change the transmission and reflection spectra of the metamaterial. The metamaterial's colossal electro-optical response (on the order of 10(-5)-10(-6) m V(-1)) allows for either fast continuous tuning of its optical properties (up to 8% optical signal modulation at up to megahertz rates) or high-contrast irreversible switching in a device only 100 nm thick, without the need for external polarizers and analysers.
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Affiliation(s)
- Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK
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24
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Buchnev O, Ou JY, Kaczmarek M, Zheludev NI, Fedotov VA. Electro-optical control in a plasmonic metamaterial hybridised with a liquid-crystal cell. Opt Express 2013; 21:1633-8. [PMID: 23389148 DOI: 10.1364/oe.21.001633] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We experimentally demonstrate efficient electro-optical control in an active nano-structured plasmonic metamaterial hybridised with a liquid-crystal cell. The hybridisation was achieved by simultaneously replacing the polarizer, transparent electrode and molecular alignment layer of the liquid-crystal cell with the metamaterial nano-structure. With the control signal of only 7 V we have achieved a fivefold hysteresis-free modulation of metamaterial transmission at the wavelength of 1.55 µm.
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Affiliation(s)
- O Buchnev
- Optoelectronics Research Centre, University of Southampton, SO17 1BJ, UK
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25
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Adamo G, Ou JY, So JK, Jenkins SD, De Angelis F, MacDonald KF, Di Fabrizio E, Ruostekoski J, Zheludev NI. Electron-beam-driven collective-mode metamaterial light source. Phys Rev Lett 2012; 109:217401. [PMID: 23215613 DOI: 10.1103/physrevlett.109.217401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Indexed: 05/12/2023]
Abstract
We demonstrate experimentally that the energy from a highly localized free-electron-beam excitation can be converted via a planar plasmonic metamaterial to a low-divergence free-space light beam. This emission, which emanates from a collectively oscillating coupled metamolecule nanoantenna ensemble much larger in size than the initial excitation, is distinctly different from cathodoluminescence and bears some similarity with laser light. It offers a novel, flexible paradigm for the development of scalable, threshold-free light sources.
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Affiliation(s)
- G Adamo
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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26
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Abstract
We show that a plasmonic metamaterial can act as a far-field to near-field transformer that focuses a free-space beam of light into a subwavelength energy hot spot at a prescribed location with a spot size only a small fraction of the wavelength. The hot spot position on the metamaterial can be prescribed and moved at will from one metamolecule of the array to another in a "digital" fashion simply by modulating the input phase profile, thus providing new opportunities for imaging and optical data processing.
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Affiliation(s)
- T S Kao
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
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27
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Abstract
We demonstrate high-finesse plasmonic metamaterial with strong resonant response in the near-IR spectral range fabricated using a thin low-loss film of gold monocrystal. The monocrystal was grown using specially formulated simplified crystal growth procedure based on epitaxial deposition, which makes it readily accessible to both plasmonics and metamaterials communities.
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Affiliation(s)
- V A Fedotov
- Optoelectronics Research Centre, University of Southampton, SO17 1BJ, UK.
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28
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Ren M, Jia B, Ou JY, Plum E, Zhang J, MacDonald KF, Nikolaenko AE, Xu J, Gu M, Zheludev NI. Nanostructured plasmonic medium for terahertz bandwidth all-optical switching. Adv Mater 2011; 23:5540-5544. [PMID: 22021040 DOI: 10.1002/adma.201103162] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Indexed: 05/27/2023]
Abstract
Periodic nanostructuring can enhance the optical nonlinearity of plasmonic metals by several orders of magnitude. By patterning a gold film, the largest sub-100 femtosecond nonlinearity is achieved, which is suitable for terahertz rate all-optical data processing as well as ultrafast optical limiters and saturable absorbers.
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Affiliation(s)
- Mengxin Ren
- Optoelectronics Research Centre, University of Southampton, UK
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29
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Zhang J, Ou JY, Papasimakis N, Chen Y, Macdonald KF, Zheludev NI. Continuous metal plasmonic frequency selective surfaces. Opt Express 2011; 19:23279-23285. [PMID: 22109206 DOI: 10.1364/oe.19.023279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In the microwave part of the spectrum, where losses are minimal, metal films regularly patterned (perforated) on the sub-wavelength scale achieve spectral selectivity by balancing the transmission and reflection characteristics of the surface. Here we show for optical frequencies, where joule losses are important, that periodic structuring of a metal film without violation of continuity (i.e. without perforation) is sufficient to achieve substantial modification of reflectivity. By engineering the geometry of the structure imposed on a surface one can dramatically change the perceived color of the metal without employing any form of chemical modification, thin-film coating or diffraction effects. This novel frequency selective effect is underpinned by plasmonic Joule losses in the constituent elements of the patterns (dubbed 'intaglio' and 'bas relief' metamaterials to distinguish indented and raised structures respectively) and is specific to the optical part of the spectrum. It has the advantage of maintaining the integrity of metal surfaces and is well suited to high-throughput fabrication via techniques such as nano-imprint.
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Affiliation(s)
- Jianfa Zhang
- Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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30
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Abstract
We introduce mechanically reconfigurable photonic metamaterials (RPMs) as a flexible platform for realizing metamaterial devices with reversible and large-range tunable characteristics in the optical part of the spectrum. Here we illustrate this concept for a temperature-driven RPM exhibiting reversible relative transmission changes of up to 50%.
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Affiliation(s)
- J Y Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, SO17 1BJ, United Kingdom.
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31
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Tanaka K, Plum E, Ou JY, Uchino T, Zheludev NI. Multifold enhancement of quantum dot luminescence in plasmonic metamaterials. Phys Rev Lett 2010; 105:227403. [PMID: 21231422 DOI: 10.1103/physrevlett.105.227403] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Indexed: 05/15/2023]
Abstract
We report that hybridizing semiconductor quantum dots with plasmonic metamaterial leads to a multifold intensity increase and narrowing of their photoluminescence spectrum. The luminescence enhancement is a clear manifestation of the cavity quantum electrodynamics Purcell effect and can be controlled by the metamaterial's design. This observation is an essential step towards understanding loss compensation in plasmonic metamaterials with gain media and for developing metamaterial-enhanced gain media.
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Affiliation(s)
- K Tanaka
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom.
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32
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Ou JY, Yang SM, Luo GY, Shen XF, Hu SY, Li CM. [Local anesthetic effect of bupivacaine in ophthalmic operations]. Yan Ke Xue Bao 1987; 3:69-71. [PMID: 3508118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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