ORCID Profile
0009-0006-4762-703X
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Publisher: AIP Publishing
Date: 11-2022
DOI: 10.1063/5.0118263
Abstract: Engineering the chiroptical responses of artificial nanostructures is vital for realizing applications in the fields of optical devices, enantioselective separation, and bio-sensing. Here, by utilizing the nano-kirigami based meta-molecule arrays, the flexible engineering of circular dichroism (CD) is achieved in the near-infrared wavelength region by the excitation of chiral surface lattice resonances (SLRs). It is found that the chiral SLRs can be flexibly tailored by a tiny structural perturbation. As a result, the wavelength, intensity, and sign of CD peak/dip can be abruptly engineered. Specifically, a CD peak with the value of +0.44 is evolved into a CD dip with an intensity of −0.66 when the etching silt length of the meta-molecules is simply decreased by 190 nm. Importantly, such CD reversal is experimentally demonstrated with the nano-kirigami method without requiring the inversion of geometric chirality. Moreover, it is found that the asymmetric dielectric environment around the meta-molecules can significantly suppress the chiral SLRs, providing an insightful understanding of the chiral SLR. Such flexible tailoring of the CD with chiral SLRs paves a versatile way toward the manipulation of chiral light–matter interactions and chiroptical functional devices.
Publisher: Wiley
Date: 16-01-2020
Abstract: 2D metasurfaces have emerged as a paradigm-shifting platform for light management with considerable miniaturization and alleviated fabrication challenges than their 3D counterparts. However, the appearance of in-plane mirror symmetry and reduced dimensions impose fundamental restraints to advanced chiroptical responses and reconfiguration capabilities. Here, a new concept of Fano-enhanced circular dichroism by introducing a reconfigurable stereo metasurface, which possesses deformable out-of-plane twists that are readily achieved by a simple nano-kirigami fabrication method, is demonstrated. The stereo height and twisting geometries can be reproducibly controlled, providing a facile and automated fashion to tailor the distinct profiles of Fano resonances under circularly polarized incidence. As a result, a recorded high efficiency of circular dichroism generation per unit s le thickness is achieved with Fano resonances in opposite lineshapes. Leveraging this feature, large-range reconfiguration of circular dichroism at optical wavelengths is demonstrated through reversible compression of the stereo metasurfaces with a fiber tip. The studied stereo metasurface unfolds a new degree of freedom for advanced photonic applications in a quasi-flat optical platform, and the proposed concept of Fano-enhanced circular dichroism opens new venues to explore interesting fundamental phenomena of chiral optics.
Publisher: Optica Publishing Group
Date: 09-09-2021
DOI: 10.1364/OE.434321
Abstract: Metasurfaces, with artificially designed ultrathin and compact optical elements, enable versatile manipulation of the litude, phase, and polarization of light waves. While most of the metasurfaces are static and passive, here we propose a reprogrammable metasurface based on the state-of-art electromechanical nano-kirigami, which allows for independent manipulation of pixels at visible wavelengths through mechanical deformation of the nanostructures. By incorporating electrostatic forces between the top suspended gold nano-architectures and bottom silicon substrate, out-of-plane deformation of each pixel and the associated phase retardation are independently controlled by applying single voltage to variable pixels or exerting programmable voltage distribution on identical pixels. As a proof-of-concept demonstration, the metasurfaces are digitally controlled and a series of tunable metasurface holograms such as 3D dynamic display and ultrathin planar lenses are achieved at visible wavelengths. The proposed electromechanical metasurface provides a new methodology to explore versatile reconfigurable and programmable functionalities that may lead to advances in a variety of applications such as hologram, 3D displays, data storage, spatial light modulations, and information processing.
Publisher: Optica Publishing Group
Date: 29-09-2021
DOI: 10.1364/OE.441464
Abstract: Circular dichroism (CD), as one of the most representative chiroptical effects, provides a simple strategy for the detection and characterization of the molecular chirality. The enhancement and sign reversal of CD are of great importance for its practical applications in chiral bio-sensing, chirality switching and optical filtering, etc. Here, we realize considerable adjustments and the sign reversal of CD in quasi-three-dimensional (quasi-3D) combined Archimedean spiral nanostructures. With special local and lattice configurations, the nanostructures have both right-handed and left-handed geometric chirality, which are designed based on the proximity effect of stencil lithography. We find that the CD response of the nanostructures becomes obvious once its height exceeds 200 nm and can be adjusted by the further increase of the height or the change of the blade spacing of the nanostructures. The CD reversal is achieved by utilizing the competition of two chiral centers when the height or blade spacing exceeds a critical value. Further analysis of the scattering power of multipole moments reveals that the CD modulation is determined by both magnetic dipole moment and electric quadrupole moment. Benefiting from the highly sensitive CD response to the height, the extreme sign reversal of CD is achieved when a sub-10-nm ultrathin medium layer is anchored on the surface of the nanostructures, which provides a promising strategy for ultra-sensitive chiral bio-sensing.
Publisher: Wiley
Date: 22-11-2023
Abstract: Fractals are beautiful forms of geometric patterns, usually having high degrees of freedom of shape change. Recently, fractal and fractal‐like designs have aroused great interest in scientific research. Here, fractal‐like nano‐kirigami structures with rotational symmetries are proposed and demonstrated, in which topological morphologies can be transformed by growing fans and coiling units. Experimentally, the nano‐kirigami structures with different fractals are manipulated by using the capillary force‐induced 3D deformation process. Benefited from the fractal‐like designs, the structral deformations exhibit strong fractal dependence, with which the stress threshold and reflection spectrum can be tailored by changing the number of fans and coiling units. The modulation of fractal nano‐kirigami is further demonstrated by using the electrostatic forces when external voltage is applied. The fractal nano‐kirigami structures are also envisioned with capability of conveniently generating fractal‐dependent optical vortices. The special fractal design strategy in this work can bring new opportunities to functional 3D micro/nano structures with improved optical tunability and customization.
Publisher: Walter de Gruyter GmbH
Date: 11-01-2023
Abstract: Nano-kirigami method enables rich ersity of structural geometries that significantly broaden the functionalities of optical micro/nano-devices. However, the methodologies of various nano-kirigami are still limited and as a result, the chiral nano-kirigami structure has yet been pushed to the limit for operation at visible wavelength region. Here, the merits of the various nano-kirigami strategies are comprehensively explored and bio-inspired nano-cilia metasurface with enhanced circular dichroism at visible wavelengths is demonstrated. The stereo chiral nano-cilia metasurface is designed with three-fold rotational symmetry, which exhibits tuneable chiroptical responses when the nano-cilia are deformed to form strong chiral light–matter interactions. By employing electron-beam lithography (EBL) and focused ion beam (FIB) lithography, on-chip nano-cilia metasurfaces are experimentally realized in near-infrared wavelengths region and at visible wavelengths, respectively, successfully validating the giant circular dichroism revealed in simulations. Our work is useful to broaden the existing platform of micro/nano-scale manufacturing and could provide an effective method for the realization of versatile bioinspired nanostructures with profound chiroptical responses.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 2022
Abstract: Dynamic color display can be realized by tunable optical metasurfaces based on the compositional or structural control. However, it is still a challenge to realize the efficient modulation by a single-field method. Here, we report a novel compositional and mechanical dual-altered rechargeable metasurface for reversible and broadband optical reconfiguration in both visible and near-infrared wavelength regions. By employing a simple fabrication and integration strategy, the continuous optical reconfiguration is manipulated through an electro-chemo-mechanical coupled process in a lithium ion battery, where lithiation and delithiation processes occur dynamically under a low electric voltage (≤1.5 V). By controlling the phase transformation from Si to Li x Si, both structural morphology and optical scattering could be rapidly and dramatically tailored within 30 s, exhibiting high-contrast colorization and decolorization in a large-area nanofilm and showing long cyclic stability. Significant wide-angle reconfiguration of high-resolution structural colors in bowtie metasurfaces is demonstrated from anomalous reflection. The results provide a multifield mechanism for reconfigurable photonic devices, and the new platform can be introduced to the multidimensional information encryption and storage.
Publisher: Springer Science and Business Media LLC
Date: 26-02-2021
DOI: 10.1038/S41467-021-21565-X
Abstract: Kirigami, with facile and automated fashion of three-dimensional (3D) transformations, offers an unconventional approach for realizing cutting-edge optical nano-electromechanical systems. Here, we demonstrate an on-chip and electromechanically reconfigurable nano-kirigami with optical functionalities. The nano-electromechanical system is built on an Au/SiO 2 /Si substrate and operated via attractive electrostatic forces between the top gold nanostructure and bottom silicon substrate. Large-range nano-kirigami like 3D deformations are clearly observed and reversibly engineered, with scalable pitch size down to 0.975 μm. Broadband nonresonant and narrowband resonant optical reconfigurations are achieved at visible and near-infrared wavelengths, respectively, with a high modulation contrast up to 494%. On-chip modulation of optical helicity is further demonstrated in submicron nano-kirigami at near-infrared wavelengths. Such small-size and high-contrast reconfigurable optical nano-kirigami provides advanced methodologies and platforms for versatile on-chip manipulation of light at nanoscale.
Publisher: AIP Publishing
Date: 08-2023
DOI: 10.1063/5.0158261
Abstract: Surface lattice resonances (SLRs) are the coherent collective interactions between periodically arranged nanoparticles, which are generally considered to be formed by the resonant electric dipole, magnetic dipole, or electric quadrupole moments of a single nanoparticle coupled with the Rayleigh anomaly (RA). Here we reveal the first observation of the chiral SLRs that are formed by the coupling of the chiral toroidal electric dipole (TED) moment and RA mode through the theoretical design and experimental fabrication of a nano-kirigami based propeller metasurface. By engineering the rotational symmetry of the propeller, e.g., from C2 (C3) symmetry to C4 symmetry, we find that the electric dipole (electric quadrupolar) chiral SLRs have evolved into the TED associated chiral SLRs. Furthermore, it is found that the excitation litude of the TED moment can be tailored by controlling the stereo twisted height of the propeller and the spin of the incident light. Finally, the chiral TED moment enhanced circular dichroism is verified in the near-infrared wavelength region. Our study provides an effective yet simple scheme to manipulate the TED-dependent chiral SLRs, paving the way toward exploring the unconventional physical properties of TED and advanced chiroptical physics.
Publisher: AIP Publishing
Date: 05-2022
DOI: 10.1063/5.0085981
Abstract: Chirality reversal between enantiomers is of great importance in both fundamental science and practical applications in chiroptics, biomedicine, and analytical chemistry. Here, we demonstrate an abrupt sign reversal of circular dichroism (CD) between artificial plasmonic diastereoisomers, which are a kind of stereo twisted metamolecules with different strength of deformations. The sign of the CD response is reversed in the same wavelength region by simply engineering the deformation height of nanostructures. Electromagnetic multipolar analysis shows that the sign of CD is determined by the phase-controlled handedness-dependent excitations of electric quadrupole modes. The numerical simulations are further verified by experiments using a nano-kirigami fabrication method. This work reveals that under certain circumstances, the CD response of the plasmonic diastereoisomers can be very close to that of enantiomers, which is useful for the exploration of profound chiroptics, as well as for the applications in chirality switching, chiral biosensing, and chiral separation.
Publisher: Optica Publishing Group
Date: 08-09-2021
DOI: 10.1364/OME.438996
Abstract: Reconfigurable three-dimensional (3D) nanostructures possess additional spatial freedom and rich physical characteristics compared with their two-dimensional (2D) counterparts. Here we demonstrate a facile and automated nano-kirigami method to create the 3D deformed spiral metasurfaces, which can flexibly manipulate optical waves by simply applying external voltages. Through etching Archimedean spirals into Au/SiO 2 /Si layer, multi-order localized surface plasmon resonances are excited within the spiral nanoslits and are dynamically tuned by floating the nanopatterns and employing the electrostatic forces, which induces a reflection modulation contrast as high as 189%. The 2D-to-3D transformation induces a strong modification of the optical chirality in both aspects of spatial distributions and strength. Importantly, the Pancharatnam-Berry (PB) geometric phase can be carefully designed and dynamically broken in the 2π range by rotating the direction of the spiral units, which results in the dynamic construction and erasing of metasurface holograms. The proposed scheme of tuning plasmonic nanoslits and breaking PB geometric phase by employing the electromechanical deformation provides a new degree of freedom for reconfigurable photonic systems, as well as dynamic applications in quasi-flat optical platforms.
Publisher: AIP Publishing
Date: 15-06-2022
DOI: 10.1063/5.0091180
Abstract: Nano-kirigami-based deformable metasurfaces offer unique advantages in the dynamic modulation of optical fields and the realization of reconfigurable micro-/nano-optoelectronic devices. Here, we theoretically propose and numerically demonstrate a magnetically actuated deformation scheme for 2D nano-kirigami structures, which can be accurately and continuously transformed from 2D to 3D. Based on the traditional pinwheel structure, an Fe/Au bilayer anti-pinwheel nanostructure is designed and dynamically transformed by employing magnetic attraction in numerical simulations, in which the ratio between deformation height and lateral period could reach up to 0.563. More importantly, it is found that the anti-pinwheel structure has superior circular dichroism (CD), whose maximum CD response could reach 7 times that of the corresponding pinwheel structure. Further analysis of the scattering power of multipole moments reveals that such a superior CD response is found to be induced by the handedness-dependent excitation of a toroidal dipole moment. Such a straightforward magnetically actuated deformation and novel anti-pinwheel structure provides useful methodologies to explore and realize deformable metamaterials and their dynamic regulation capabilities, as well as applications in chiral spectroscopy, optical reconfiguration, optical sensing, etc.
Publisher: American Chemical Society (ACS)
Date: 19-11-2021
Abstract: Molecular chirality recognition plays a pivotal role in chiral generation and transfer in living systems and makes important contribution to the development of erse applications spanning from chiral separation to soft nanorobots. To detect chirality recognition, most of the molecular sensors described to date are based on the design and preparation of the host-guest complexation with chromophore or fluorophore at the reporter unit. Nevertheless, the involved tedious procedures and complicated chemical syntheses h er their practical applications. Here, we report the plasmonically chiroptical detection of molecular chirality recognition without the need for a chromophore or fluorophore unit. This facile methodology is based on plasmonic nanotransducers that can convert molecular chirality recognitions occurring at nanoscale interfaces into asymmetrically lified plasmonic circular dichroism readouts, enabling enantiospecific recognition and quantitative determination of the enantiomeric excess of small amino acids. Importantly, such a plasmon-based chirality sensing shows 10
Publisher: Wiley
Date: 24-09-2021
Abstract: Artificial chiral structures play a crucial role in the realization of strong chiroptical responses and flexible light manipulation. Here, a unique bi‐chiral propeller metamolecule array is demonstrated in which the geometric chirality of the subunit with intracellular blades is opposite to that of the subunit with intercellular blades. Benefited from the special propeller twists, it is demonstrated that the propeller metamolecule arrays support the phase controlled chiral surface lattice resonances, whose litude can be tailored by tuning the coupling of chiral centers to change the interference phase. Specifically, the circular dichroism of the metamolecule array is readily reversed by rotating the propeller blades without changing the local geometry and the lattice parameters. The proposed bi‐chiral propeller metamolecule array and the exotic circular dichroism reversal are further demonstrated in experiments by adopting a nano‐kirigami fabrication method. This work provides a novel paradigm to investigate the profound chiroptical responses and manipulate the advanced spin states of light.
Publisher: American Chemical Society (ACS)
Date: 10-08-2021
No related grants have been discovered for Chang-Yin Ji.