Showing papers by "Yuri S. Kivshar published in 2015"
TL;DR: In this paper, all-dielectric Huygens' metasurfaces are demonstrated for NIR frequencies using arrays of silicon nanodisks as metaatoms.
Abstract: Optical metasurfaces have developed as a breakthrough concept for advanced wave-front engineering enabled by subwavelength resonant nanostructures. However, reflection and/or absorption losses as well as low polarization-conversion efficiencies pose a fundamental obstacle for achieving high transmission efficiencies that are required for practical applications. Here, for the first time to our knowledge, highly efficient all-dielectric metasurfaces are demonstrated for NIR frequencies using arrays of silicon nanodisks as metaatoms. The main features of Huygens' sources are employed, namely, spectrally overlapping crossed electric and magnetic dipole resonances of equal strength, to demonstrate Huygens' surfaces with full transmission-phase coverage of 360° and near-unity transmission. Full-phase coverage combined with high efficiency in transmission are experimentally confirmed. Based on these key properties, all-dielectric Huygens' metasurfaces can become a new paradigm for flat optical devices, including beam-steering, beam-shaping, and focusing, as well as holography and dispersion control.
1,159 citations
TL;DR: It is demonstrated experimentally that dielectric nanoparticles can exhibit a radiationless anapole mode in visible, and the spectral overlap of the toroidal and electric dipole modes is achieved through a geometry tuning.
Abstract: The work of A.E.M. was supported by the Australian Research Council via Future
Fellowship program (FT110100037). The authors at DSI were supported by DSI core
funds. Fabrication, Scanning Electron Microscope Imaging and NSOM works were
carried out in facilities provided by SnFPC@DSI (SERC Grant 092 160 0139). Zhen Ying
Pan (DSI) is acknowledged for SEM imaging. Yi Zhou (DSI) is acknowledged for silicon
film growth. Leonard Gonzaga (DSI), Yeow Teck Toh (DSI) and Doris Ng (DSI) are
acknowledged for development of the silicon nanofabrication procedure. B.N.C.
acknowledges support from the Government of Russian Federation, Megagrant No.
14.B25.31.0019.
685 citations
TL;DR: It is demonstrated that non-Hermiticity dramatically modifies the structure of modes and spectral degeneracies in exciton-polariton systems, and, therefore, will affect their quantum transport, localization and dynamical properties.
Abstract: Exciton-polaritons are hybrid light-matter quasiparticles formed by strongly interacting photons and excitons (electron-hole pairs) in semiconductor microcavities. They have emerged as a robust solid-state platform for next-generation optoelectronic applications as well as for fundamental studies of quantum many-body physics. Importantly, exciton-polaritons are a profoundly open (that is, non-Hermitian) quantum system, which requires constant pumping of energy and continuously decays, releasing coherent radiation. Thus, the exciton-polaritons always exist in a balanced potential landscape of gain and loss. However, the inherent non-Hermitian nature of this potential has so far been largely ignored in exciton-polariton physics. Here we demonstrate that non-Hermiticity dramatically modifies the structure of modes and spectral degeneracies in exciton-polariton systems, and, therefore, will affect their quantum transport, localization and dynamical properties. Using a spatially structured optical pump, we create a chaotic exciton-polariton billiard--a two-dimensional area enclosed by a curved potential barrier. Eigenmodes of this billiard exhibit multiple non-Hermitian spectral degeneracies, known as exceptional points. Such points can cause remarkable wave phenomena, such as unidirectional transport, anomalous lasing/absorption and chiral modes. By varying parameters of the billiard, we observe crossing and anti-crossing of energy levels and reveal the non-trivial topological modal structure exclusive to non-Hermitian systems. We also observe mode switching and a topological Berry phase for a parameter loop encircling the exceptional point. Our findings pave the way to studies of non-Hermitian quantum dynamics of exciton-polaritons, which may uncover novel operating principles for polariton-based devices.
498 citations
TL;DR: In this article, the most interesting properties of photonic metasurfaces are reviewed, demonstrating their useful functionalities such as frequency selectivity, wavefront shaping, polarization control, etc.
Abstract: Optical metasurfaces are thin-layer subwavelength-patterned structures that interact strongly with light. Metasurfaces have become the subject of several rapidly growing areas of research, being a logical extension of the field of metamaterials towards their practical applications. Metasurfaces demonstrate many useful properties of metadevices with engineered resonant electric and magnetic optical responses combined with low losses of thin-layer structures. Here we introduce the basic concepts of this rapidly growing research field that stem from earlier studies of frequency-selective surfaces in radiophysics, being enriched by the recent development of metamaterials and subwavelength nanophotonics. We review the most interesting properties of photonic metasurfaces, demonstrating their useful functionalities such as frequency selectivity, wavefront shaping, polarization control, etc. We discuss the ways to achieve tunability of metasurfaces and also demonstrate that nonlinear effects can be enhanced with the help of metasurface engineering.
444 citations
TL;DR: It is shown that undesirable free-carrier effects can be suppressed by a proper spectral positioning of the magnetic resonance, making such a structure the fastest all-optical switch operating at the nanoscale.
Abstract: We demonstrate experimentally ultrafast all-optical switching in subwavelength nonlinear dielectric nanostructures exhibiting localized magnetic Mie resonances. We employ amorphous silicon nanodisks to achieve strong self-modulation of femtosecond pulses with a depth of 60% at picojoule-per-disk pump energies. In the pump–probe measurements, we reveal that switching in the nanodisks can be governed by pulse-limited 65 fs-long two-photon absorption being enhanced by a factor of 80 with respect to the unstructured silicon film. We also show that undesirable free-carrier effects can be suppressed by a proper spectral positioning of the magnetic resonance, making such a structure the fastest all-optical switch operating at the nanoscale.
389 citations
TL;DR: A functional silicon metadevice at telecom wavelengths that can efficiently control the wavefront of optical beams by imprinting a spatially varying transmittance phase independent of the polarization of the incident beam is experimentally demonstrated.
Abstract: We experimentally demonstrate a functional silicon metadevice at telecom wavelengths that can efficiently control the wavefront of optical beams by imprinting a spatially varying transmittance phase independent of the polarization of the incident beam. Near-unity transmittance efficiency and close to 0–2π phase coverage are enabled by utilizing the localized electric and magnetic Mie-type resonances of low-loss silicon nanoparticles tailored to behave as electromagnetically dual-symmetric scatterers. We apply this concept to realize a metadevice that converts a Gaussian beam into a vortex beam. The required spatial distribution of transmittance phases is achieved by a variation of the lattice spacing as a single geometric control parameter.
376 citations
TL;DR: For the first time, hotspots of the magnetic field at visible wavelengths for light polarized across the nanodimer's primary axis are observed using near-field scanning optical microscopy.
Abstract: The authors at DSI
were supported by DSI core funds. The work at ITMO
University was financially supported by Government of Russian
Federation (projects 14.584.21.0009 10, Zadanie no.
3.561.2014/K, 074-U01) and Russian Foundation for Basic
Research.
357 citations
TL;DR: Dynamic tuning of electric and magnetic resonances in all-dielectric silicon nanodisk metasurfaces in the telecom spectral range based on the temperature-dependent refractive-index change of a nematic liquid crystal is experimentally demonstrated.
Abstract: All-dielectric metasurfaces provide a powerful platform for highly efficient flat optical devices, owing to their strong electric and magnetic dipolar response accompanied by negligible losses at near-infrared frequencies. Here we experimentally demonstrate dynamic tuning of electric and magnetic resonances in all-dielectric silicon nanodisk metasurfaces in the telecom spectral range based on the temperature-dependent refractive-index change of a nematic liquid crystal. We achieve a maximum resonance tuning range of 40 nm and a pronounced change in the transmittance intensity up to a factor of 5. Strongly different tuning rates are observed for the electric and the magnetic response, which allows for dynamically adjusting the spectral mode separation. Furthermore, we experimentally investigate the influence of the anisotropic (temperature-dependent) dielectric environment provided by the liquid crystal on both the electric and magnetic resonances. We demonstrate that the phase transition of the liquid cry...
353 citations
TL;DR: It is revealed an outstanding potential of water as an inexpensive, abundant and bio-friendly high-refractive-index material for creating tunable all-dielectric photonic structures and metamaterials.
Abstract: We reveal an outstanding potential of water as an inexpensive, abundant and bio-friendly high-refractive-index material for creating tunable all-dielectric photonic structures and metamaterials. Specifically, we demonstrate thermal, mechanical and gravitational tunability of magnetic and electric resonances in a metamaterial consisting of periodically positioned water-filled reservoirs. The proposed water-based metamaterials can find applications not only as cheap and ecological microwave devices, but also in optical and terahertz metamaterials prototyping and educational lab equipment.
172 citations
TL;DR: The approach is illustrated by a general equivalent scheme, and it allows resenting the Purcell factor through the continuous radiation of a small antenna at the presence of an electromagnetic environment.
Abstract: The Purcell effect is defined as a modification of the spontaneous emission rate of a quantum emitter at the presence of a resonant cavity. However, a change of the emission rate of an emitter caused by an environment has a classical counterpart. Any small antenna tuned to a resonance can be described as an oscillator with radiative losses, and the effect of the environment on its radiation can be modeled and measured in terms of the antenna radiation resistance, similar to a quantum emitter. We exploit this analogue behavior to develop a general approach for calculating the Purcell factors of different systems and various frequency ranges including both electric and magnetic Purcell factors. Our approach is illustrated by a general equivalent scheme, and it allows resenting the Purcell factor through the continuous radiation of a small antenna at the presence of an electromagnetic environment.
164 citations
TL;DR: A novel type of photonic topological edge states in zigzag arrays of dielectric nanoparticles based on optically induced magnetic Mie resonances is suggested and the ability to control the subwavelength topologically protected electromagnetic edge modes by changing the polarization of the incident wave is demonstrated.
Abstract: This work was supported by the Australian
Research Council, the Government of the Russian Federation
(Grant No. 074-U01), the Dynasty Foundation (Russia),
and the Russian Fund for the Basic Research. A. P. S.
acknowledges a support of the SPIE scholarship. A. N. P.
acknowledges a support of the President Grant of
the Russian Federation (No. MK-6029.2014.2).
TL;DR: In this paper, the authors studied the third-harmonic generation from low-loss subwavelength silicon nanodisks arranged in the form of trimer oligomers with varying distance between the nanoparticles.
Abstract: It is known that the nonlinear optical properties of photonic nanostructures can be modified substantially due to strong field confinement and optical resonances. In this contribution, we study third-harmonic generation from low-loss subwavelength silicon nanodisks arranged in the form of trimer oligomers with varying distance between the nanoparticles. Each of the nanodisks exhibits both electric and magnetic Mie-type resonances that are shown to affect significantly the nonlinear response. We observe the third-harmonic radiation intensity that is comparable to that of a bulk silicon slab and demonstrate a pronounced reshaping of the third-harmonic spectra due to interference of the nonlinearly generated waves augmented by an interplay between the electric and the magnetic dipolar resonances.
TL;DR: In this article, the authors show that hyperbolic metasurfaces support simultaneous propagation of both quasi-TE and quasi-TM plasmon surface modes of ''hybrid''' polarization at the same frequency.
Abstract: The authors show theoretically that hyperbolic metasurfaces support simultaneous propagation of both quasi-TE and quasi-TM plasmon surface modes of ``hybrid''' polarization at the same frequency --- a two-dimensional analog of D'yakonov surface waves. The shape of their equal-frequency contours depends drastically on the frequency and changes from elliptical to hyperbolic, and so a topological transition takes place.
TL;DR: In this paper, the authors measured the near-infrared photoluminescence spectra of colloidal quantum dots coupled to the localized electric and magnetic resonances of subwavelength silicon nanodisks.
Abstract: We measure the near-infrared photoluminescence spectra of colloidal quantum dots coupled to the localized electric and magnetic resonances of subwavelength silicon nanodisks. The spectral position of the resonances with respect to each other is controlled via the nanodisk geometry. We observe a strong influence of the nanodisk resonance positions on the quantum dot photoluminescence spectra. For separate resonances, the spectral density observed in transmittance measurements correlates with the spectral range covered by a broad emission spectrum. For the case of spectral overlap of the electric and magnetic dipolar resonances we enter a new regime for coupling, where the characteristic transparency effect evident in the transmittance spectra is accompanied by a pronounced single emission maximum. Our experimental observations are in good qualitative agreement with numerical calculations.
TL;DR: In this paper, the effect of a substrate on the optical properties of high-refractive-index dielectric nanoparticles was studied, both numerically and analytically, and it was shown that the optical response of subwavelength nanoparticles can be effectively modeled in the dipole approximation when the dielectrics particle is replaced by a pair of point electric and magnetic dipoles with modified polarizabilities.
Abstract: We study, both numerically and analytically, the effect of a substrate on the optical properties of high-refractive-index dielectric nanoparticles. We demonstrate that the optical response of subwavelength nanoparticles can be effectively modeled in the dipole approximation when the dielectric particle is replaced by a pair of point electric and magnetic dipoles with modified polarizabilities. Based on our model, we reveal the existence of the substrate-induced bianisotropic interaction (magnetoelectric coupling) between electric and magnetic dipole modes, which is strongly enhanced near the corresponding dipole resonances. This results in a specific feature of the radiation pattern that can be employed to identify the effective bianisotropic interaction experimentally.
TL;DR: It is shown that a periodic photonic structure transforms into a metamaterial when the Mie gap opens up below the lowest Bragg bandgap where the homogenization approach can be justified and the effective permeability becomes negative.
Abstract: Photonic crystals and dielectric metamaterials represent two different classes of artificial media but are often composed of similar structural elements. The question is how to distinguish these two types of periodic structures when their parameters, such as permittivity and lattice constant, vary continuously. Here we discuss transition between photonic crystals and dielectric metamaterials and introduce the concept of a phase diagram, based on the physics of Mie and Bragg resonances. We show that a periodic photonic structure transforms into a metamaterial when the Mie gap opens up below the lowest Bragg bandgap where the homogenization approach can be justified and the effective permeability becomes negative. Our theoretical approach is confirmed by microwave experiments for a metacrystal composed of tubes filled with heated water. This analysis yields deep insight into the properties of periodic structures, and provides a useful tool for designing different classes of electromagnetic materials with variable parameters.
TL;DR: In this article, the second-order nonlinear response from resonant metasurfaces composed of metal-dielectric nanodisks is investigated. And the authors demonstrate that by exciting the resonant optical modes of the composite nanoparticles, they can achieve a strong enhancement of the secondharmonic signal from the metaurface.
Abstract: We study, both experimentally and theoretically, the second-order nonlinear response from resonant metasurfaces composed of metal–dielectric nanodisks. We demonstrate that by exciting the resonant optical modes of the composite nanoparticles we can achieve strong enhancement of the second-harmonic signal from the metasurface. By employing a multipole expansion method for the generated second-harmonic radiation, we show that the observed SHG enhancement is due to the magnetic dipolar and electric quadrupolar second-order nonlinear response of the metasurface.
TL;DR: It is demonstrated that the suppression of light scattering for any direction of observation can be achieved for a uniform dielectric object with high refractive index, in a sharp contrast to the cloaking with multilayered plasmonic structures suggested previously.
Abstract: Subwavelength structures demonstrate many unusual optical properties which can be employed for engineering of a new generation of functional metadevices, as well as controlled scattering of light and invisibility cloaking. Here we demonstrate that the suppression of light scattering for any direction of observation can be achieved for a uniform dielectric object with high refractive index, in a sharp contrast to the cloaking with multilayered plasmonic structures suggested previously. Our finding is based on the novel physics of cascades of Fano resonances observed in the Mie scattering from a homogeneous dielectric rod. We observe this effect experimentally at microwaves by employing high temperature-dependent dielectric permittivity of a glass cylinder with heated water. Our results open a new avenue in analyzing the optical response of high-index dielectric nanoparticles and the physics of cloaking.
TL;DR: In this article, it was shown that breaking the symmetry of an all-dielectric nanoparticle leads to a geometrically tunable magnetoelectric coupling, i.e., an omega-type bianisotropy.
Abstract: The study of high-index dielectric nanoparticles currently attracts a lot of attention. They do not suffer from absorption but promise to provide control of the properties of light comparable to plasmonic nanoparticles. To further advance the field, it is important to identify versatile dielectric nanoparticles with unconventional properties. Here, we show that breaking the symmetry of an all-dielectric nanoparticle leads to a geometrically tunable magnetoelectric coupling, i.e., an omega-type bianisotropy. The suggested nanoparticle exhibits different backscatterings and, as an interesting consequence, different optical scattering forces for opposite illumination directions. An array of such nanoparticles provides different reflection phases when illuminated from opposite directions. With a proper geometrical tuning, this bianisotropic nanoparticle is capable of providing a $2\ensuremath{\pi}$ phase change in the reflection spectrum while possessing a rather large and constant amplitude. This allows the creation of reflectarrays with near-perfect transmission out of the resonance band due to the absence of a usually employed metallic screen.
TL;DR: It is demonstrated that such edge states can be selectively excited with the linear polarization of the incident light, and visualize them directly by near-field scanning optical microscopy.
Abstract: We report on the first experimental observation of topological edge states in zigzag chains of plasmonic nanodisks. We demonstrate that such edge states can be selectively excited with the linear polarization of the incident light, and visualize them directly by near-field scanning optical microscopy. Our work provides experimental verification of a novel paradigm for manipulating light at the nanoscale in topologically nontrivial structures.
TL;DR: In this paper, the Mie resonances of high-index dielectric nanoparticles have been studied for controlling both magnetic and electric response of structured matter by engineering the MIE resonances in high index dielectrics.
Abstract: We review a new, rapidly developing field of all-dielectric nanophotonics which allows to control both magnetic and electric response of structured matter by engineering the Mie resonances in high-index dielectric nanoparticles. We discuss optical properties of such dielectric nanoparticles, methods of their fabrication, and also recent advances in all-dielectric metadevices including couple-resonator dielectric waveguides, nanoantennas, and metasurfaces.
TL;DR: In this article, the interplay between collective and individual optically induced magnetic responses in quadrumers made of identical dielectric nanoparticles is studied and the existence of magnetic Fano resonance in nanophotonics is verified.
Abstract: We study the interplay between collective and individual optically induced magnetic responses in quadrumers made of identical dielectric nanoparticles. Unlike their plasmonic counterparts, all-dielectric nanoparticle clusters are shown to exhibit multiple dimensions of resonant magnetic responses that can be employed for the realization of anomalous scattering signatures. We focus our analysis on symmetric quadrumers made from silicon nanoparticles and verify our theoretical results in proof-of-concept radio frequency experiments demonstrating the existence of a novel type of magnetic Fano resonance in nanophotonics.
TL;DR: An ultracompact plasmonic spectral-band demultiplexer for telecommunication wavelengths integrated onto an optical waveguide that couples two wavelength-encoded optical signals in the O- and the C-band in opposite directions of a silicon waveguide is suggested and realized.
Abstract: Here we suggest and realize an ultracompact plasmonic spectral-band demultiplexer for telecommunication wavelengths integrated onto an optical waveguide that couples two wavelength-encoded optical signals in the O- and the C-band in opposite directions of a silicon waveguide In this way, we demonstrate a plasmonic key element for on-chip optical data processing that can also be used as a functional link between on- and off-chip optical signals
TL;DR: In this article, both magnetic and electric optically induced resonances of silicon nanoparticles were studied experimentally by combining polarization-resolved dark-field spectroscopy and near-field scanning optical microscopy measurements.
Abstract: We study experimentally both magnetic and electric optically induced resonances of silicon nanoparticles by combining polarization-resolved dark-field spectroscopy and near-field scanning optical microscopy measurements We reveal that the scattering spectra exhibit strong sensitivity of electric dipole response to the probing beam polarization and attribute the characteristic asymmetry of measured near-field patterns to the excitation of a magnetic dipole mode The proposed experimental approach can serve as a powerful tool for the study of photonic nanostructures possessing both electric and magnetic optical responses
TL;DR: It is demonstrated that an enhancement in the intensity of the Eu3+ magnetic dipole emission was observed for emitters located in close vicinity to a gold nanohole array designed to support plasmonic resonances overlapping with the emission spectrum of the ions.
Abstract: We demonstrate the enhancement of magnetic dipole spontaneous emission from Eu3+ ions by an engineered plasmonic nanostructure that controls the electromagnetic environment of the emitter. Using an optical microscope setup, an enhancement in the intensity of the Eu3+ magnetic dipole emission was observed for emitters located in close vicinity to a gold nanohole array designed to support plasmonic resonances overlapping with the emission spectrum of the ions.
TL;DR: This work uses experimental material data and a genetic algorithm to reduce the total scattering of all-dielectric multilayer structures by adjusting the material and thickness of various layers for several types of dielectric cores at telecommunication wavelengths.
Abstract: We study optical response of all-dielectric multilayer structures and demonstrate that the total scattering of such structures can be suppressed leading to optimal invisibility cloaking. We use experimental material data and a genetic algorithm to reduce the total scattering by adjusting the material and thickness of various layers for several types of dielectric cores at telecommunication wavelengths. Our approach demonstrates 80-fold suppression of the total scattering cross-section by employing just a few dielectric layers.
TL;DR: In this article, a broad range of problems involving nonlinear PT-symmetric photonic systems with an intensity-dependent refractive index are discussed, including the formation of localized modes, nonlinearly-induced PT symmetry breaking, and all-optical switching.
Abstract: One of the challenges of the modern photonics is to develop all-optical devices enabling increased speed and energy efficiency for transmitting and processing information on an optical chip. It is believed that the recently suggested Parity-Time (PT) symmetric photonic systems with alternating regions of gain and loss can bring novel functionalities. In such systems, losses are as important as gain and, depending on the structural parameters, gain compensates losses. Generally, PT systems demonstrate nontrivial non-conservative wave interactions and phase transitions, which can be employed for signal filtering and switching, opening new prospects for active control of light. In this review, we discuss a broad range of problems involving nonlinear PT-symmetric photonic systems with an intensity-dependent refractive index. Nonlinearity in such PT symmetric systems provides a basis for many effects such as the formation of localized modes, nonlinearly-induced PT-symmetry breaking, and all-optical switching. Nonlinear PT-symmetric systems can serve as powerful building blocks for the development of novel photonic devices targeting an active light control.
TL;DR: In this paper, the authors introduce an approach for enhancing the nonlinear response of graphene through its resonant coupling to a plasmonic metasurface via cascaded Fano resonances.
Abstract: We introduce an important approach for enhancing the nonlinear response of graphene through its resonant coupling to a plasmonic metasurface via cascaded Fano resonances. Such a hybrid metasurface supports two types of subradiant resonant modes, i.e., asymmetric modes of structured metamaterial elements (``metamolecules'') and graphene plasmons exhibiting strong mutual coupling and avoided dispersion crossing. We demonstrate that the tunability of graphene plasmons facilitates the strong interaction between the subradiant modes, modifying the spectral position and lifetime of the Fano resonances. We reveal that a strong resonant interaction, combined with the subwavelength localization of plasmons, leads to an enhanced nonlinear response and high efficiency of the second-harmonic generation.
TL;DR: This study analytically, numerically and experimentally investigate metasurfaces with different lattice arrangements and uncover the influence of lattice disorder on their electromagnetic properties, resulting in an adequate description of the scattering properties of amorphous metAsurfaces, paving the way for their integration into future applications.
Abstract: Understanding the impact of order and disorder is of fundamental importance to perceive and to appreciate the functionality of modern photonic metasurfaces. Metasurfaces with disordered and amorphous inner arrangements promise to mitigate problems that arise for their counterparts with strictly periodic lattices of elementary unit cells such as, e.g., spatial dispersion, and allows the use of fabrication techniques that are suitable for large scale and cheap fabrication of metasurfaces. In this study, we analytically, numerically and experimentally investigate metasurfaces with different lattice arrangements and uncover the influence of lattice disorder on their electromagnetic properties. The considered metasurfaces are composed of metal-dielectric-metal elements that sustain both electric and magnetic resonances. Emphasis is placed on understanding the effect of the transition of the lattice symmetry from a periodic to an amorphous state and on studying oblique illumination. For this scenario, we develop a powerful analytical model that yields, for the first time, an adequate description of the scattering properties of amorphous metasurfaces, paving the way for their integration into future applications.
TL;DR: In this paper, the authors demonstrate nearly perfect suppression of scattering from arbitrary-shaped objects in spatially dispersive metamaterial acting as an alignment-free concealing cover, in both forward and backward directions.
Abstract: Concealing objects by making them invisible to an external electromagnetic probe is coined by the term ``cloaking.'' Cloaking devices, having numerous potential applications, are still facing challenges in realization, especially in the visible spectral range. In particular, inherent losses and extreme parameters of metamaterials required for the cloak implementation are the limiting factors. Here, we numerically demonstrate nearly perfect suppression of scattering from arbitrary-shaped objects in spatially dispersive metamaterial acting as an alignment-free concealing cover. We consider a realization of a metamaterial as a metal-dielectric multilayer and demonstrate suppression of scattering from an arbitrary object in forward and backward directions with perfectly preserved wave fronts and less than 10% absolute intensity change, despite spatial dispersion effects present in the composite metamaterial. Beyond the usual scattering suppression applications, the proposed configuration may be used for a simple realization of scattering-free detectors and sensors.