Conventional optical components rely on gradual phase shifts accumulated during light propagation to shape beams. New degrees of freedom are attained by introducing abrupt changes over the scale wavelength. A two-dimensional array resonators with spatially varying response and subwavelength separation can imprint such discontinuities propagating as it traverses interface between two media. Anomalous reflection refraction phenomena observed in this regime optically thin arrays metallic...

The concept of optical phase discontinuities is applied to the design and demonstration aberration-free planar lenses axicons, comprising a phased array ultrathin subwavelength spaced antennas. axicons consist radial distributions V-shaped nanoantennas that generate respectively spherical wavefronts non-diffracting Bessel beams at telecom wavelengths. Simulations are also presented show our designs applicable high numerical aperture such as flat microscope objectives.

We demonstrate optically thin quarter-wave plates built with metasurfaces that generate high-quality circularly polarized light over a broad wavelength range for arbitrary orientation of the incident linear polarization. The metasurface consists an array plasmonic antennas spatially varying phase and polarization responses. Experimentally demonstrated high degree circular (>0.97) from λ = 5 to 12 μm, representing major advance in performance compared previously reported plasmonics-based wave plates.

This article reviews recent progress leading to the realization of planar optical components made a single layer phase shifting nanostructures. After introducing principles optics and discussing earlier works on subwavelength diffractive optics, we introduce classification metasurfaces based their different mechanisms profiles comparison between plasmonic dielectric metasurfaces. We place particular emphasis developments electric magnetic field control light with nanostructures highlight...

Color correcting planar optics The functionality of many bulk optical elements can now be replaced by specially designed structures fabricated in thin films. This approach, however, has generally been applicable to only a narrow band wavelengths. Aieta et al. show that chromatic dispersion, or color dependence, compensated for the judicious design surface. results demonstrate general approach fabrication broadband and lightweight engineered into Science , this issue p. 1342

We show that perfect absorption can be achieved in a system comprising single lossy dielectric layer of thickness much smaller than the incident wavelength on an opaque substrate by utilizing nontrivial phase shifts at interfaces between media. This design is implemented with ultra-thin (∼λ/65) vanadium dioxide (VO2) sapphire, temperature tuned vicinity VO2 insulator-to-metal transition, leading to 99.75% λ = 11.6 μm. The structural simplicity and large tuning range (from ∼80% 0.25%...

Plasmonic antennas enable the conversion of light from free space into subwavelength volumes and vice versa, which facilitates manipulation at nanoscale. Dynamic control properties is desirable for many applications, including biochemical sensors, reconfigurable meta-surfaces compact optoelectronic devices. The combination metallic structures graphene, has gate-voltage dependent optical properties, emerging as a possible platform electrically controlled plasmonic In this paper, we...

Experiments on ultrathin anisotropic arrays of subwavelength optical antennas display out-of-plane refraction. A powerful three-dimensional (3D) extension the recently demonstrated generalized laws refraction and reflection shows that interface imparts a tangential wavevector to incident light leading anomalous beams, which in general are noncoplanar with beam. The refracted beam direction can be controlled by varying angle between plane incidence antenna array.

A flat optical device that generates vortices with a variety of topological charges is demonstrated. This spatially modulates light beams over distance much smaller than the wavelength in direction propagation by means an array V-shaped plasmonic antennas sub-wavelength separation. Optical are shown to develop after from array, feature has major potential implications for integrated optics.

Abstract Allowing subwavelength-scale-digitization of optical wavefronts to achieve complete control light at interfaces, metasurfaces are particularly suited for the realization planar phase-holograms that promise new applications in high-capacity information technologies. Similarly, use orbital angular momentum as a degree freedom processing can further improve bandwidth communications. However, due lack selectivity design conventional holograms, their utilization an carrier holography has...

Nanoscale optical resonators enable a new class of flat components called metasurfaces. This approach has been used to demonstrate functionalities such as focusing free monochromatic aberrations (i.e., spherical and coma), anomalous reflection, large circular dichroism. Recently, dielectric metasurfaces that compensate the phase dispersion responsible for chromatic have demonstrated. Here, we utilize an aperiodic array coupled nanoresonators multiwavelength achromatic lens. The focal length...

Abstract Geometric-phase metasurfaces, recently utilized for controlling wavefronts of circular polarized (CP) electromagnetic waves, are drastically limited to the cross-polarization modality. Combining geometric with propagation phase allows further control co-polarized output channel, nevertheless addressing only similar functionality on both outputs two different CP incident beams. Here we introduce concept chirality-assisted as a degree freedom, which could decouple outputs, and thus be...

Conventional optical components rely on the propagation effect to control phase and polarization of light beams. One can instead exploit abrupt changes associated with scattered from resonators propagation. In this paper, we discuss responses anisotropic plasmonic antennas a new class planar ("metasurfaces") based arrays these antennas. To demonstrate versatility metasurfaces, show design experimental realization number flat components: 1) metasurfaces constant interfacial gradient that...

We report a new type of holographic interface, which is able to manipulate the three fundamental properties light (phase, amplitude, and polarization) over broad wavelength range. The design strategy relies on replacing large openings conventional holograms by arrays subwavelength apertures, oriented locally select particular state polarization. resulting optical element can therefore be viewed as superposition two independent structures with very different length scales, that is, hologram...

We demonstrate that the resonances of infrared plasmonic antennas can be tuned or switched on/off by taking advantage thermally driven insulator-to-metal phase transition in vanadium dioxide (VO2). Y-shaped were fabricated on a 180 nm film VO2 deposited sapphire substrate, and their shown to depend temperature proximity its transition, good agreement with full-wave simulations. achieved tunability resonance wavelength approximately 10% (>1 μm at λ∼10 μm).

Upon reflection, modulate phase Metasurfaces provide a platform to fabricate optical devices in compact form much thinner than their corresponding bulk components. Recognizing that metasurfaces are also open systems interacting with environment, Song et al . designed metasurface exploits those non-Hermitian properties such they can encircle an exceptional point. Subsequent scattering from point was shown be polarization dependent, thus providing additional control knob designing for wave...

Thermal radiation from conventional emitters, such as the warm glow of a light bulb, increases with temperature: hotter more it glows. emitters that buck this trend could lead to many unconventional thermal devices. Researchers have engineered (meta)material by exploiting unique structural and electronic phase changes vanadium oxide at around 70${}^{\ensuremath{\circ}}$C.

Abstract Controlling light properties with diffractive planar elements requires full-polarization channels and accurate reconstruction of optical signal for real applications. Here, we present a general method that enables wavefront shaping arbitrary output polarization by encoding both phase information into pixelated metasurfaces. We apply this concept to convert an input plane wave linear holographic image spatial polarization. A vectorial ptychography technique is introduced mapping the...

Optimization of the performance flat optical components, also dubbed metasurfaces, is a crucial step towards their implementation in realistic systems. Yet, most design techniques, which rely on large parameter search to calculate scattering response elementary building blocks, do not account for near-field interactions that strongly influence device performance. In this work, we exploit two advanced optimization techniques based statistical learning and evolutionary strategies together with...

Abstract Electromagnetic metasurface cloaks provide an alternative paradigm toward rendering arbitrarily shaped scatterers invisible. Most transformation-optics (TO) intrinsically need wavelength-scale volume/thickness, such that the incoming waves could have enough long paths to interact with structured meta-atoms in cloak region and consequently restore wavefront. Other challenges of TO include polarization-dependent operation avoid singular parameters composite cloaking materials...

Abstract In recent years, metasurfaces have emerged as revolutionary tools to manipulate the behavior of light at nanoscale. These devices consist nanostructures defined within a single layer metal or dielectric materials, and they offer unprecedented control over optical properties light, leading previously unattainable applications in flat lenses, holographic imaging, polarimetry, emission control, amongst others. The operation principles metaoptics include complex light–matter...