Optical metasurfaces,i.e.arrays of nanoantennas with sub-wavelength size and separation,enable the manipulation of light-matter interactions in miniaturized optical components with no classical counterparts.Six decade...Optical metasurfaces,i.e.arrays of nanoantennas with sub-wavelength size and separation,enable the manipulation of light-matter interactions in miniaturized optical components with no classical counterparts.Six decades after the first ob-servation of the second harmonic generation(SHG)in bulk crystals,these devices are expected to break new ground in the field of nonlinear optics,shifting the focus from the phase matching approach achieved within long propagation dis-tances to that of near-field resonances interplay in leaky nanocavities.Here we review the recent progress in SHG with all-dielectric metasurfaces.We discuss the most used technological platforms which underpinned such advances and analyze different SHG control approaches.We finally compare their performances with other well-established technolo-gies,with the hope to delineate the current state-of-the-art and figure out a few scenarios in which these devices might soon offer unprecedented opportunities.展开更多
The synthesis, structure and properties of a new A5B4O15-type cation-deficient perovskite Ba3La2Ti2Ta2O15 were discribed. The compound was prepared by the conventional solid-state reaction route. The phase and structu...The synthesis, structure and properties of a new A5B4O15-type cation-deficient perovskite Ba3La2Ti2Ta2O15 were discribed. The compound was prepared by the conventional solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）. The results reveal that the compound is successfully synthesized. The compound crystallizes in the trigonal system with unit cell parameter a=5.6730（2） A, c=11.6511（2） A, V=324.93（1） A^3 and Z=1. The microwave dielectric properties of the ceramic are studied using a network analyzer, and it shows a high dielectric constant of 45.1, a high quality factors with Q×fof21 029 GHz, and a positive τf of 5.3 ppm℃^-1.展开更多
Dielectric optical antennas have emerged as a promising nanophotonic architecture for manipulating the propagation and localization of light.However,the optically induced Mie resonances in an isolated nanoantenna are ...Dielectric optical antennas have emerged as a promising nanophotonic architecture for manipulating the propagation and localization of light.However,the optically induced Mie resonances in an isolated nanoantenna are normally with broad spectra and poor𝑄-factors,limiting their performances in sensing,lasing,and nonlinear optics.Here,we dramatically enhance the𝑄-factors of Mie resonances in silicon(Si)nanoparticles across the optical band by arranging the nanoparticles in a periodic lattice.We select monocrystalline Si with negligible material losses and develop a unique method to fabricate nanoparticle arrays on a quartz substrate.By extinction dispersion measurements and electromagnetic analysis,we can identify three types of collective Mie resonances with𝑄-factors∼500 in the same nanocylinder arrays,including surface lattice resonances,bound states in the continuum,and quasi-guided modes.Our work paves the way for fundamental research in strong light-matter interactions and the design of highly efficient light-emitting metasurfaces.展开更多
A series of new microwave dielectric ceramics Ba3-nLa1+nTinNb3-nO12 (n=0,1,2) were prepared in the BaO-La2O3-TiO2-Nb2O5 system by high temperature solid-state reaction route. The phase and structure of the ceramics we...A series of new microwave dielectric ceramics Ba3-nLa1+nTinNb3-nO12 (n=0,1,2) were prepared in the BaO-La2O3-TiO2-Nb2O5 system by high temperature solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction, scanning electron microscope, and microwave dielectric properties measurements. These samples were identified as single phase and adopted A4B3O12-type cation-deficient hexagonal perovskite structure, which can be described as consisting of identical perovskite-like blocks, three corner-sharing BO6 octahedra thick, separated by layers of vacant octahedral. These ceramics have high dielectric constants in the range of 48-42, high quality factors (Q×f) up to 38 000 GHz, and low temperature coefficient of resonant frequencies (τf) in the range of (-40-+6)×10-6℃-1. With increasing content of La and Ti, the dielectric constants slightly decrease butτf gradually increases.展开更多
In this paper,we demonstrate a method of designing all-dielectric metamaterial frequency selective surface(FSS)with ceramic resonators in spatial arrangement.Compared with the traditional way,spatial arrangement provi...In this paper,we demonstrate a method of designing all-dielectric metamaterial frequency selective surface(FSS)with ceramic resonators in spatial arrangement.Compared with the traditional way,spatial arrangement provides a flexible way to handle the permutation and combination of different ceramic resonators.With this method,the resonance response can be adjusted easily to achieve pass/stop band effects.As an example,a stop band spatial arrangement all-dielectric metamaterial FSS is designed.Its working band is in 11.65–12.23 GHz.By adjusting permittivity and geometrical parameters of ceramic resonators,we can easily modulate the resonances,band pass or band stop characteristic,as well as the working band.展开更多
基金financial support by ANR through the NANOPAIR project.
文摘Optical metasurfaces,i.e.arrays of nanoantennas with sub-wavelength size and separation,enable the manipulation of light-matter interactions in miniaturized optical components with no classical counterparts.Six decades after the first ob-servation of the second harmonic generation(SHG)in bulk crystals,these devices are expected to break new ground in the field of nonlinear optics,shifting the focus from the phase matching approach achieved within long propagation dis-tances to that of near-field resonances interplay in leaky nanocavities.Here we review the recent progress in SHG with all-dielectric metasurfaces.We discuss the most used technological platforms which underpinned such advances and analyze different SHG control approaches.We finally compare their performances with other well-established technolo-gies,with the hope to delineate the current state-of-the-art and figure out a few scenarios in which these devices might soon offer unprecedented opportunities.
基金Funded by the National Natural Science Foundation of China(No.20571059 and No.50572078)Opening Foundation of Key Laboratory of New Processing Technology for Nonferrous Metals and Materials,Ministry of Education
文摘The synthesis, structure and properties of a new A5B4O15-type cation-deficient perovskite Ba3La2Ti2Ta2O15 were discribed. The compound was prepared by the conventional solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）. The results reveal that the compound is successfully synthesized. The compound crystallizes in the trigonal system with unit cell parameter a=5.6730（2） A, c=11.6511（2） A, V=324.93（1） A^3 and Z=1. The microwave dielectric properties of the ceramic are studied using a network analyzer, and it shows a high dielectric constant of 45.1, a high quality factors with Q×fof21 029 GHz, and a positive τf of 5.3 ppm℃^-1.
基金the National Natural Science Foundation of China(62120106001,62275184,61875143,and 62104165)the Natural Science Foundation of Jiangsu Province(BK20200859,BK20200857,and BK20210713)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.JGR and PB also acknowledge financial support from Nederlandse Organisatie voor Wetenschappelijk Onderzoek(NWO)(Vici 680-47-628).
文摘Dielectric optical antennas have emerged as a promising nanophotonic architecture for manipulating the propagation and localization of light.However,the optically induced Mie resonances in an isolated nanoantenna are normally with broad spectra and poor𝑄-factors,limiting their performances in sensing,lasing,and nonlinear optics.Here,we dramatically enhance the𝑄-factors of Mie resonances in silicon(Si)nanoparticles across the optical band by arranging the nanoparticles in a periodic lattice.We select monocrystalline Si with negligible material losses and develop a unique method to fabricate nanoparticle arrays on a quartz substrate.By extinction dispersion measurements and electromagnetic analysis,we can identify three types of collective Mie resonances with𝑄-factors∼500 in the same nanocylinder arrays,including surface lattice resonances,bound states in the continuum,and quasi-guided modes.Our work paves the way for fundamental research in strong light-matter interactions and the design of highly efficient light-emitting metasurfaces.
基金Projects(50572078, 20571059) supported by the National Natural Science Foundation of China
文摘A series of new microwave dielectric ceramics Ba3-nLa1+nTinNb3-nO12 (n=0,1,2) were prepared in the BaO-La2O3-TiO2-Nb2O5 system by high temperature solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction, scanning electron microscope, and microwave dielectric properties measurements. These samples were identified as single phase and adopted A4B3O12-type cation-deficient hexagonal perovskite structure, which can be described as consisting of identical perovskite-like blocks, three corner-sharing BO6 octahedra thick, separated by layers of vacant octahedral. These ceramics have high dielectric constants in the range of 48-42, high quality factors (Q×f) up to 38 000 GHz, and low temperature coefficient of resonant frequencies (τf) in the range of (-40-+6)×10-6℃-1. With increasing content of La and Ti, the dielectric constants slightly decrease butτf gradually increases.
基金Natural Science Foundation of China(NSFC)through the grant nos.11504428,61671466 and 11274389Natural Science Foundation of Shaanxi Province under Grant 2016JM6026.
文摘In this paper,we demonstrate a method of designing all-dielectric metamaterial frequency selective surface(FSS)with ceramic resonators in spatial arrangement.Compared with the traditional way,spatial arrangement provides a flexible way to handle the permutation and combination of different ceramic resonators.With this method,the resonance response can be adjusted easily to achieve pass/stop band effects.As an example,a stop band spatial arrangement all-dielectric metamaterial FSS is designed.Its working band is in 11.65–12.23 GHz.By adjusting permittivity and geometrical parameters of ceramic resonators,we can easily modulate the resonances,band pass or band stop characteristic,as well as the working band.
