Spatial polarization converter can shift the state of incident wave to another in a specific frequency band. The traditional conversion devices mainly include natural materials and artificial electromagnetic (EM) structures, which are generally sensitive states cannot realize manipulations nonlinear harmonics. These drawbacks limit their developments wireless communications radar detection applications. Herein, general regulation scheme based on anisotropic time‐domain digital coding...

Polarization control of electromagnetic (EM) waves is vital in imaging and wireless communication systems. In this communication, we propose a broadband polarization-reconfigurable converter (BPRC) based on active metasurfaces, which can achieve conversion under both linear-polarization (LP) circular-polarization (CP) incident wide bands by changing the states p-i-n diodes. The BPRC composed three-layer metal patches, dielectric substrates, When diodes are OFF-state, LP CP be converted into...

Abstract Independent controls of various properties electromagnetic (EM) waves are crucially required in a wide range applications. Programmable metasurface is promising candidate to provide an advanced platform for manipulating EM waves. Here, we propose approach that can arbitrarily control the polarization direction and phases reflected linear nonlinear ways using stacked programmable metasurface. Further, extend space-time-coding theory incorporate dimension polarization, which provides...

Abstract Metasurfaces have garnered significant attention for the ability to manipulate electromagnetic (EM) waves, enabling diverse applications such as beam steering, frequency conversion, and vortex‐wave generation. However, achieving complete control of EM properties phase, amplitude, polarization momentum over multiple frequencies remains a challenge. Here, an asynchronous space‐time‐coding digital metasurface (ASTCM) is proposed tackle By segmenting into distinct partitions letting...

Abstract Polarization and phase are two essential properties of electromagnetic (EM) waves. A transmissive metasurface is proposed that can simultaneously manipulate the polarization EM The design has a powerful capability rotating to any desired azimuth direction for linearly polarized (LP) wave achieving cross‐polarization conversion circularly (CP) wave. Meanwhile, transmission be dynamically controlled CP composed types substrate‐integrated waveguides (SIW) in cross arrangement, which an...

Inverse design of nanoparticles for desired scattering spectra and dynamic switching between the two opposite anomalies, i.e. superscattering invisibility, is important in realizing cloaking, sensing functional devices. However, traditionally process quite complicated, which involves complex structures with many choices synthetic constituents dispersions. Here, we demonstrate that a well-trained deep-learning neural network can handle these issues efficiently, not only forwardly predict...

Abstract Polarization and phase manipulations have gained widespread applications across various fields. The emergence of metasurface provides a new platform for the manipulation electromagnetic waves. However, most metasurfaces are limited to modulating only one single property. Here, coding that achieves 1‐bit both co‐polarized cross‐polarized reflected waves linear circular polarization wave excitations. Notably, proposed enables responses incident electric fields with arbitrary...

Abstract The Cassegrain telescope, made of a concave primary mirror and convex secondary mirror, is widely utilized for modern astronomical observation. However, the existence curved mirrors inevitably results in bulky configurations. Here, we propose new design miniaturized telescope by replacing with planar reflective metasurfaces. focusing imaging properties metasurface telescopes are experimentally verified circularly polarized incident light at near infrared wavelengths. concept can be...

The polarizations of electromagnetic (EM) waves are very important for transceivers. We propose a broadband polarization-insensitive polarization rotator (PIPR), which can realize 90° rotation incident with an arbitrary azimuth angle. A unit the PIPR is composed two types substrate integrated waveguide (SIW) units in checkerboard pattern, provides more than -0.2 dB transmission from 9.5 to 10.9 GHz. electric field inside cavity analyzed explain working mechanism proposed rotator. prototype...

Reflective objectives are widely used in many imaging systems, but can hardly be compact, due to their curved mirrors. To address this problem, the authors planarize mirrors a Cassegrain-style objective by substituting geometric-phase-based flat metasurfaces for conventional These reflective metasurface intrinsically free of residual light, and thus less demanding terms precision illumination nanofabrication, compared refractive metalenses. This planar design potentially reshape simplify...

Polarization Synthesis A general polarization regulation scheme based on anisotropic time-domain digital coding metasurface is proposed by Qiang Cheng, Shi Jin, Tie Jun Cui, and co-workers in article number 2000060. Both linear nonlinear syntheses their real-time programmable controls can be achieved, which offers a new approach to expand the scope of regulation. An designed fabricated validate feasibility scheme. It expected find important applications novel wireless communication radar systems.

In this study, a perfect metamaterial absorber based on strontium titanate and bulk Dirac semimetals is proposed. When the temperature of was 300K, dual-band absorptions were 99.74% 99.99% at 1.227 1.552 THz, respectively. The sensitivities transverse magnetic (TM) wave 0.95 1.22 GHz/K; sensitivity electric (TE) 0.76 GHz/K. TE TM waves modulated by inserting semimetal between concave convex devices. modulation depth 97.9% 1.1 THz; extinction ratio 16.9 dB. 1.435 THz 95.9%; 13.89 13.98...

Abstract Polarization independent Mie scattering of building blocks is fundamental for constructions optical systems with robust functionalities. Conventional studies such polarization independence are generally restricted to special states either linear or circular polarizations, widely neglecting elliptically‐polarized that generically present in realistic applications. Here, a comprehensive recipe achieve invariant properties terms cross sections plane waves arbitrary polarizations...

Second harmonic generation (SHG) is a coherent nonlinear phenomenon that plays an important role in laser color conversion. Lithium niobate (LN), which features both large band gap and outstanding second-order nonlinearities, acts as optical material for frequency conversion covering wide spectral range from ultraviolet to mid-infrared. Here we experimentally demonstrate LN metasurfaces with controllable SHG properties. Distinct enhancements the efficiency are observed at Mie-resonances. And...

To implement full‐wave simulation of electromagnetic wave impinging invisible cloaks, an efficient multidomain pseudospectral time‐domain algorithm is developed in this study. The proposed method solves the same forms Maxwell's equations both regular and cloaking areas, then applies different methods to update electric magnetic field components, respectively. new requires less grid points per wavelength, meanwhile, strategy relieves complicated treatment components based on Yee grids within...

Curved reflective mirrors play an indispensable role in widely-employed Cassegrain-type optics, which consequently are inevitably bulky, and thus neither integratable nor well extendable. Through substituting geometric phase based metasurfaces for curved mirrors, here a planar Schwarzschild objective is obtained, with both the focusing imaging functionalities experimentally verified. The achieved intrinsically free of residual light imposes less stringent restrictions on illuminating...

Optical properties of nonmagnetic structures that support artificial optically-induced magnetic responses have recently attracted surging interest. Here we conduct symmetry-dictated investigations into scattering particles from perspectives electromagnetic duality with discrete geometric rotations. For arbitrary configurations, reveal far-field patterns are invariant under transformations, which in particular means self-dual clusters random particle distributions polarization independent....

Polarization is an essential property of electromagnetic waves that has numerous applications in various fields. We introduce this article a metasurface capable rotating linear wave polarization to any azimuth angle. This consists two types substrate-integrated waveguides. crossed form and exhibits high conversion efficiency from 5.9 6.6 GHz. One key advantage the proposed design its ability maintain regardless rotation angle, making it excellent candidate for use wireless communication...

Exploiting the phase transition of vanadium dioxide (VO2), a switchable terahertz multifunctional device integrating narrowband absorption and broadband polarization switching was proposed in our study. The transformation VO2 from insulating state to metallic can realize different functions. When metal state, metamaterial exhibited an effect exceeding 90% range 1.96 4.06 THz, its amplitude tunable via changing conductivity VO2. Further, modulation depth reached 171%. This also used as...

In the paper, a new type of cylindrical waveguide with RHM core and LHM cladding is proposed to study mechanism slow down light wave. terms cancellation total power flow at interface between right-handed left-handed materials, propagation can be reached. Our results show that appropriate permeability ratio or negative permeability, waves fully stopped in such waveguide. Drude model used finding frequency which wave stopped.