共查询到20条相似文献，搜索用时 15 毫秒
1.
Feifan Wang Zi Wang Dun Mao Mingkun Chen Qiu Li Thomas Kananen Dustin Fang Anishkumar Soman Xiaoyong Hu Craig B. Arnold Tingyi Gu 《Advanced Optical Materials》2020,8(8)
Subwavelength periodic confinement can collectively and selectively enhance local light intensity and enable control over the photoinduced phase transformations at the nanometer scale. Standard nanofabrication process can result in geometrical and compositional inhomogeneities in optical phase change materials, especially chalcogenides, as those materials exhibit poor chemical and thermal stability. Here the self‐assembled planar chalcogenide nanostructured array is demonstrated with resonance‐enhanced light emission to create an all‐dielectric optical metasurface, by taking advantage of the fluid properties associated with solution‐processed films. A patterned silicon membrane serves as a template for shaping the chalcogenide metasurface structure. Solution‐processed arsenic sulfide metasurface structures are self‐assembled in the suspended 250 nm silicon membrane templates. The periodic nanostructure dramatically manifests the local light–matter interaction such as absorption of incident photons, Raman emission, and photoluminescence. Also, the thermal distribution is modified by the boundaries and thus the photothermal crystallization process, leading to the formation of anisotropic nanoemitters within the field enhancement area. This hybrid structure shows wavelength‐selective anisotropic photoluminescence, which is a characteristic behavior of the collective response of the resonant‐guided modes in a periodic nanostructure. The resonance‐enhanced Purcell effect can manifest the quantum efficiency of localized light emission. 相似文献
2.
Ming Lun Tseng Zhan‐Hong Lin Hsin Yu Kuo Tzu‐Ting Huang Yi‐Teng Huang Tsung Lin Chung Cheng Hung Chu Jer‐Shing Huang Din Ping Tsai 《Advanced Optical Materials》2019,7(15)
Metasurfaces comprising 3D chiral structures have shown great potential in chiroptical applications such as chiral optical components and sensing. So far, the main challenges lie in the nanofabrication and the limited operational bandwidth. Homogeneous and localized broadband near‐field optical chirality enhancement has not been achieved. Here, an effective nanofabrication method to create a 3D chiral metasurface with far‐ and near‐field broadband chiroptical properties is demonstrated. A focused ion beam is used to cut and stretch nanowires into 3D Archimedean spirals from stacked films. The 3D Archimedean spiral is a self‐similar chiral fractal structure sensitive to the chirality of light. The spiral exhibits far‐ and near‐field broadband chiroptical responses from 2 to 8 µm. With circularly polarized light (CPL), the spiral shows superior far‐field transmission dissymmetry and handedness‐dependent near‐field localization. With linearly polarized excitation, homogeneous and highly enhanced broadband near‐field optical chirality is generated at a stably localized position inside the spiral. The effective yet straightforward fabrication strategy allows easy fabrication of 3D chiral structures with superior broadband far‐field chiroptical response as well as strongly enhanced and stably localized broadband near‐field optical chirality. The reported method and chiral metasurface may find applications in broadband chiral optics and chiral sensing. 相似文献
3.
Chunwei Hsu Riccardo Frisenda Robert Schmidt Ashish Arora Steffen Michaelis de Vasconcellos Rudolf Bratschitsch Herre S. J. van der Zant Andres Castellanos‐Gomez 《Advanced Optical Materials》2019,7(13)
An interesting aspect of 2D materials is the change of their electronic structure with the reduction of thickness. Molybdenum and tungsten‐based transition metal dichalcogenides form an important family of 2D materials, whose members show a thickness‐dependent bandgap and strong light–matter interaction. In this work, the experimental determination of the complex refractive index of 1‐, 2‐, 3‐layer thick MoS2, MoSe2, WS2, and WSe2 in the range from 400 to 850 nm of the electromagnetic spectrum is reported by using microreflectance spectroscopy and combined with calculations based on the Fresnel equations. It is further provided a comparison with the bulk refractive index values reported in the literature and a discussion of the difference/similarity between our work and the monolayer refractive index available from the literature, finding that the results from different techniques are in good agreement. 相似文献
4.
Adam J. Ollanik George Z. Hartfield Yaping Ji John T. Robertson Kazi Islam Matthew D. Escarra 《Advanced Optical Materials》2019,7(24)
The development of new optical materials and metamaterials has seen a natural progression toward both nanoscale geometries and dynamic performance. The development of these materials, such as optical metasurfaces which impart discrete, spatially dependent phase shifts on incident light, often benefits from the measurement of transmitted or reflected phase. Careful measurement of phase typically proves difficult to implement, due to high measurement sensitivity to practically unavoidable environmental sources of noise and drift. To date, no characterization technique has yet emerged as a frontrunner for these applications. This challenge is addressed using a custom‐designed three‐beam Mach–Zehnder interferometer capable of continuously referenced measurement of both phase and transmittance, resulting in a 10× reduction of noise and drift and phase measurement standard deviation over 10 min of 0.56° and over 16 h of 2.8°. High measurement stability provided by this method enables samples to be easily characterized under dynamic conditions. Temperature‐dependent measurements are demonstrated with phase‐change material vanadium dioxide (VO2), and with wavelength‐dependent measurements of a dielectric Huygens metasurface supporting a characteristic resonant reflection peak. A Fourier‐based signal filtering technique is applied, reducing measurement uncertainty to 0.13° and enabling discernment of monolayer thickness variations in 2D material MoS2. 相似文献
5.
《Advanced Optical Materials》2018,6(2)
As an analogue compound of black phosphorus, a new 2D semiconducting few‐layer SnS is successfully synthesized, and its nonlinear optical response is investigated. It is shown that its nonlinear refractive index and third‐order nonlinear susceptibility are measured as n2 ≈ 10−5 (cm2 W−1) and ≈ 10−10 (e.s.u.), respectively. By taking advantage of such a large Kerr nonlinearity, an all‐optical switching technique based on few‐layer SnS is realized through modulating the propagation of the signal beam by another controlling beam. The achievement of all‐optical switching indicates that few‐layer SnS could be developed as an excellent optical material for all‐optical signal processing. More importantly, a conceptually new and reliable information conversion system based on spatial cross‐phase modulation in few‐layer SnS, that is, the transmission and conversion of a sequence of bit information from one wavelength channel to the other, is presented. The contributions reveal potential applications of few‐layer SnS as a new type of optical information material, and it is therefore anticipated that SnS and other IV–VI compound‐based 2D nanomaterials could find promising applications in photonic devices such as optical modulators, optical switches, detectors, etc. 相似文献
6.
Xiaoli Sun Bingnan Shi Haoyuan Wang Na Lin Shande Liu Kejian Yang Baitao Zhang Jingliang He 《Advanced Optical Materials》2020,8(4)
2D van der Waals metal 3R phase niobium disulfide (3R‐NbS2) has fascinating anisotropic, magnetic, optical, and superconducting properties. Herein, few‐layered 2D 3R‐NbS2 nanosheets are fabricated by combining liquid phase exfoliation and spin‐coating methods. The first principles calculations are performed to explore their electronic band structures to reveal the metallic properties and enhanced optical absorption as thickness increased. The linear and nonlinear optical properties arising from the plasmonic effects and nonequilibrium electrons are studied through the violet–visible–near‐infrared absorption spectroscopy, polarization‐resolved optical microscopy, and open‐aperture Z‐scan methods. The nonlinear absorption coefficient and imaginary part of the third‐order susceptibility are determined to be −2.5 × 106 cm GW−1 and −2.4 × 10−6 esu at 1064 nm. Furthermore, 2D 3R‐NbS2 nanosheets based saturable absorbers are fabricated and applied in solid‐state pulsed lasers, in which a continuous‐wave mode‐locking laser operation at 1050.6 nm is demonstrated with a pulse duration of 302 fs. The results not only verify that 2D metallic materials, such as 3R‐NbS2, are excellent nonlinear optical modulators, but also will arouse a general interest in designing novel materials/structures with 2D metallic materials for electronic and photonic devices. 相似文献
7.
《Advanced Optical Materials》2017,5(24)
Compared with devices controlling microwave and visible light, there is a lack of functional devices for terahertz (THz) wave control. Moreover, the available THz elements are usually manufactured with bulk materials, in contrast to the trend of miniaturization and compact device requirements. Here, full control of both phase and amplitude is achieved experimentally and numerically at 0.14 THz, one of the atmospheric windows, by demonstrating the functionalities such as polarization conversion, metalenses and the generation of a non‐diffraction Airy beam. Significantly, the metal structures are fabricated on a flexible substrate with a total thickness of ≈0.063 l via a standard flexible printed circuit technique. Taking into account the considerable manipulation efficiency and cost‐efficient sample fabrication technique, the results show solid advances in the development of metasurfaces as a versatile platform for designing practical functional devices in the THz range. 相似文献
8.
Yutao Tang Zhiguang Liu Junhong Deng Kingfai Li Jiafang Li Guixin Li 《Laser u0026amp; Photonics Reviews》2020,14(7)
In linear optical regime, it is shown that the polarization, amplitude, and phase of light can be easily controlled by using optical metasurfaces, thus enabling the powerful designs of metalenses, high‐efficiency holograms, and so on. In comparison, the manipulation of nonlinear optical processes on the metasurfaces is much more challenging. This is mainly because the metasurface nonlinear source is also modulating the waves emitted from it. Thus, designing nonlinear meta‐atoms with multiple optical functionalities is highly desirable. Herein, the broadband and near‐unity nonlinear optical circular dichroism (CD) of second harmonic generation from a nano‐kirigami plasmonic metasurface is experimentally demonstrated, which is free‐standing with total thickness of about one‐third of the excitation wavelength. The broadband and near unity nonlinear CD is attributed to both the strong CD of fundamental wavelengths and spin‐controlled second harmonic generations from the nano‐kirigami meta‐atoms with threefold rotational symmetries. The proposed nonlinear nano‐kirigami metasurface provides a novel platform for realizing various nonlinear optical functionalities at the nanoscale. 相似文献
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10.
Yunzheng Wang Weichun Huang Cong Wang Jia Guo Feng Zhang Yufeng Song Yanqi Ge Leiming Wu Jie Liu Jianqing Li Han Zhang 《Laser u0026amp; Photonics Reviews》2019,13(4)
Q‐switched fiber lasers are of great interest in industrial material processing, nonlinear frequency conversion, spectroscopy etc. However, passive Q‐switching possesses drawbacks of degradation and failure of the saturable absorber and the difficulty in accurate modification of the repetition rate. To overcome these issues, active Q‐switching that can normally modulate the cavity quality‐factor by an externally‐driven Q‐switcher is in high demand. Herein, an actively Q‐switched laser with antimonene‐based all‐optical modulator is devised based on the high photo‐thermal efficiency (48%) and broadband response in antimonene. It is demonstrated that this actively modulated laser represents all‐optically tunable output parameters (e.g., output repetition rate), environmental stability, and easy synchronization. It is anticipated that this actively antimonene‐based all‐optical modulator with advantages of large modulation depth, low energy consumption, and high conversion efficiency has great potential in all‐optical information processing and pulsed laser engineering. 相似文献
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Tying isolated vortex knots in complex optical fields has been recently realized using spatial light modulators (SLMs). These traditional devices suffer from low efficiency, narrow bandwidth, and they cannot be integrated to nanophotonic systems. Here, the design and realization of metasurface holograms (MHs) is reported to efficiently generate the optical vortex knots in a broad spectral region. In comparison with conventional optical devices, the thicknesses and pixels of MHs are both in subwavelength scale, and the size of created optical vortex knot can be six orders of magnitude smaller than those produced by SLMs. Such extremely little vortex knots may find widespread applications in templating knotted micro/nano‐structures in photosensitive materials and 3D optical trapping of cold atoms in complex topologies at microscale. In particular, it is found that the spatial position of the generated off‐axis optical vortex knot is able to be symmetrically reversed by just changing the helicity of the incident light. This spin‐selective vortex knot generator can be regarded as a new type of metasurface device for manipulating the topological structure of optical vortex lines, which has potential applications in the field of singular optics. 相似文献
13.
Battulga Munkhbat Betül Küçüköz Denis G. Baranov Tomasz J. Antosiewicz Timur O. Shegai 《Laser u0026amp; Photonics Reviews》2023,17(1):2200057
Transition metal dichalcogenides (TMDs) attract significant attention due to their exceptional optical, excitonic, mechanical, and electronic properties. Nanostructured multilayer TMDs were recently shown to be highly promising for nanophotonic applications, as motivated by their exceptionally high refractive indices and optical anisotropy. Here, this vision is extended to more sophisticated structures, such as periodic arrays of nanodisks and nanoholes with ultra sharp walls, as well as proof-of-concept all-TMD waveguides and resonators. Specific focus is given to various advanced nanofabrication strategies, including careful selection of resists for electron beam lithography and etching methods, especially for non-conductiven but relevant for nanophotonic applications substrates, such as SiO2. The specific materials studied here include semiconducting WS2, in-plane anisotropic ReS2, and metallic TaSe2, TaS2, and NbSe2. The resulting nanostructures can potentially impact several nanophotonic and optoelectronic areas, including high-index nanophotonics, plasmonics and on-chip optical circuits. The knowledge of TMD material-dependent nanofabrication parameters developed here will help broaden the scope of future applications of all-TMD nanophotonics. 相似文献
14.
Cheng Luo Xiangdong Guo Hai Hu Debo Hu Chenchen Wu Xiaoxia Yang Qing Dai 《Advanced Optical Materials》2020,8(5)
Polaritons in 2D materials exhibit extensive optical phenomena, such as an ultrahigh field confinement and tunability and, thus, have been attracting increasing attentions. Many different methods have been developed to characterize and manipulate polaritons, which in turn has promoted a steady booming of this field. Here, the significant progress made in probing polaritons in 2D materials based on the characterization method, i.e., optical far‐field, optical near‐field, and (opto)electronic methods is reviewed. Perspectives on the potential development and applications of these methods are also discussed. 相似文献
15.
Summary We report the absorption edge spectra of the new family of diluted magnetic semiconductors Cd1−x
Mn
x
Ga2Se4 (0≤x≤1), grown from the vapour phase by chemical transport. Absorption bands observed under the gap of CdGa2Se4 are attributed to intra-Mn2+ transitions involving excited states of the 3d
5 electrons, split by the crystal field.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
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In this paper, an electrically tunable all‐dielectric metasurface doublet is proposed operating at mid‐infrared frequency regime with dynamic 2π phase span in transmission mode. Each layer of the metasurface consists of a periodic array of silicon nanobars configured into p‐i‐n junctions in which the double carrier injection into the intrinsic region under forward bias allows for tuning of the silicon refractive index. The physical mechanism is based on the spectral overlap of high quality factor guided mode resonances supported by each constituent layer establishing an extreme Huygens' operation regime of nearly reflectionless transmission with steep phase spectrum. The short response time of field‐driven carrier injection in p‐i‐n junctions allows for modulation of refractive index with radio‐frequency biasing signals, yielding a stable time‐modulated all‐dielectric metasurface with directional frequency conversion and harmonic generation in transmission. A systematic approach is adopted to control the output spectrum of generated frequency harmonics through engineering the temporally modulated phase of transmitted light via adjusting the modulation waveform. Specifically, pure frequency mixing and concurrent dual‐frequency generation in transmission mode are demonstrated. Unique applications of the time‐modulated all‐dielectric metasurface are presented including wavelength‐multiplexed metalens for dual‐polarity focusing/diffusing and frequency diverse transmitarray for ultrafast spatiotemporal beam‐scanning. 相似文献
18.
Davit Hakobyan Hernando Magallanes Gediminas Seniutinas Saulius Juodkazis Etienne Brasselet 《Advanced Optical Materials》2016,4(2):306-312
Submicron‐thick gold films endowed with subwavelength patterning allow on‐demand topological shaping of light, hence the precise delivery of optical orbital angular momentum. Several kinds of metallic metasurfaces enabling the generation of optical vortices with arbitrary topological charges in the visible domain are fabricated following a design based on space‐variant subwavelength grating with discrete orientational distribution. The optical performances of obtained flat spin–orbit optical elements designed to operate at 532 nm wavelength are experimentally assessed and satisfactorily compared to expectations. About 80% of optical vortex generation purity for predetermined topological charge up to is achieved. Other designs that allow continuous orientational distribution of nanogratings as well as the superposition of orbital angular momentum states are also proposed. 相似文献
19.
Growth steps and 2D nuclei are observed by AFM on the {0 0 1} faces of MnHg(SCN)4(C2H6OS)2 (MMTD) crystals. Measurements of the heights of steps and nuclei show the lowest value is equal to c/4. According to the interplanar distance modification established by Donney and Harker, the lowest height should be c/2. Appearance of the sub-layer growth is correlative with the crystal structure of MMTD. 相似文献
20.
Qiangbing Guo Kan Wu Zhengpeng Shao Endale T. Basore Peng Jiang Jianrong Qiu 《Advanced Optical Materials》2019,7(13)
Due to its unique trivalent electronic configuration, boron features richer properties as well as higher chemical and structural complexities compared with its right neighbor carbon. Consequently, over a decade later than the exfoliation of graphene, borophene has just been experimentally demonstrated on certain metal substrates and under ultrahigh‐vacuum conditions, which, however, limit its wide and in‐depth experimental researches. Here, for the first time, by employing liquid‐exfoliated boron nanosheets, all‐optical signal processing application is explored based on its superior photo‐thermal response. A stable all‐optical modulator is presented, which shows significantly faster response speed and higher modulation efficiency compared with other 2D materials‐based similar devices. Furthermore, boron nanosheets‐based all‐optical logic gating operations are also demonstrated. This work not only presents an excellent 2D material‐based all‐optical signal processing device, but also marks a significant step toward optical and photonic researches as well as device applications of 2D boron. 相似文献