Search

Converting and patterning high‐quality perovskite quantum dots (PQDs) into flexible thin films is of great significance for high‐performance solid‐state optical applications. However, the poor stability and low quantum efficiency of PQDs after film formation is a big challenge hindering their usability. Here, an in situ synthesis strategy to prepare ligand‐free long‐term stable CsPb(Br0.3I0.7)3@poly(methylmethacrylate) (PMMA) PQDs fibers with thermal responsive fluorescence performance is demonstrated. The luminescence of the CsPb(Br0.3I0.7)3@PMMA PQDs fibers can rapidly and reversibly quench and recover between heating and cooling cycles. It reveals that the thermally induced phase transition of CsPb(Br0.3I0.7)3 results in this thermally reversible luminescence phenomenon. This temperature‐reversible luminescence characteristic not only deepens the comprehension of the temperature‐dependent phase transition behavior of perovskite materials but also broadens their applications in the fields of information encryption storage, anti‐counterfeiting, temperature warning, and other temperature‐responsive fields. [ABSTRACT FROM AUTHOR]

Metamaterials consisting of subwavelength resonators offer an exciting opportunity for realizing asymmetric transmission (AT) of linearly polarized light. However, to date, only moderate/narrow‐band AT responses have been obtained in metadevices based on stacked planar nanostructures. Here, leveraging a combination of a genetic algorithm (GA) based optimization method and a membrane projection lithography (MPL) fabrication approach, a quasi‐3D metamaterial for broadband AT of linearly polarized mid‐infrared light is demonstrated. Facilitated by the customized GA, an efficient exploration of 3D plasmonic meta‐atoms with broken mirror symmetry in the light propagation direction allows the satisfaction of the rigorous conditions for AT of linearly polarized waves over a broad wavelength range. Confirmed by surface current analysis, the observed AT behavior is attributed to the resonant coupling between the plasmonic nanostructures located on the two orthogonal walls of the MPL cavities. Incorporating an advanced inverse‐design method and a state‐of‐art fabrication technique, the methodology used in the present study provides a promising route for exploiting 3D metamaterials with sophisticated functionalities via effectively exploring the high‐dimensional parametric space offered by true 3D meta‐atoms. [ABSTRACT FROM AUTHOR]

Reconfigurability is one of the most critical properties of nanophotonic systems and, consequently, methods for enabling a significant degree of functionality are highly sought after. However, dynamically responsive control in top-down fabricated photonic structures often requires extreme conditions and yields moderate modulation capability. In sharp contrast to top-down methods, directed self-assembly of micro- and nanoparticles offers a distinct avenue for reconfigurable photonics. In the present work, gold nanowire lattices are formed via electric field directed assembly in order to take advantage of their collective optical properties. The lattices are reconfigured on-demand between two different functional states, in the form of broadband polarizers. By selectively switching the electric field between two orthogonal electrode pairs, a maximum transmission contrast of ≈50% is observed in the near-infrared regime. Moreover, the reconfigurable transmission spectra, which are highly dependent on the nanowire size and electric field conditions, are reversible. The demonstrated proof-of-concept nanowire lattice polarizer provides potential for electrically reconfigurable photonic devices such as ultra-compact polarization components, electro-optic switches, and on-chip modulators. [ABSTRACT FROM AUTHOR]

The concept of invisibility has garnered long-standing interest throughout human history but has only been realized experimentally within the past decade, albeit over a limited bandwidth. While the physical wave phenomenon of a reduced scattering signature has been demonstrated with different cloaking methods such as transformation optics and scattering cancellation, such technology has yet to be incorporated into any practical real-world devices. Through the use of quasi-2D functional metasurfaces, the long-standing issue of simultaneous mutual coupling and radiation blockage is addressed that occurs when two or more electromagnetic radiators are placed in close proximity to one another. The proposed compact and ultralightweight metasurfaces, comprising arrays of subwavelength electric and magnetic resonators with tailored dispersive properties, are capable of fully restoring the intrinsic properties of real-world electromagnetic radiators when placed in a multiradiator environment. This work introduces a general design approach to bridge the gap between the theory and practice for cloaks, which is applicable to microwave, terahertz, and optical radiators, as well as acoustic and thermal sources. Moreover, this technology provides an unprecedented opportunity for enabling high-density deployment of radiating systems with low interference and undistorted signal wave fronts. [ABSTRACT FROM AUTHOR]

A correction to the article "Restoring Intrinsic Properties of Electromagnetic Radiators Using Ultralightweight Integrated Metasurface Cloaks" published in a 2015 issue of the journal "Advanced Functional Materials" is presented.