However, dielectric systems tend to have high values of Q and low values of S while plasmonic systems behave oppositely, thus limiting the achievable FOM*. Notably, hybridizing dielectric and plasmonic resonators has often been considered to circumvent this limit. [9,13-23] The resulting hybrid resonators exhibit mediocre values of Q and S and, although hybrid resonators still resemble a large ongoing field of research due to their benefits of cost efficiency, none of these hybrid resonators have shown superior performance in comparison to the individual uncoupled resonators to date. Remarkably, dielectric bound states in continuum (BICs) exhibit a higher FOM* than could be achieved by coupling of two optical resonators with initial quality factors and sensitivities Q 1 S 1 and Q 2 S 2 (see Supporting Information). [24-26] This is a conse

Optical metasurfaces address a plethora of applications in planar optics, as they enable precise control of the phase, amplitude, and polarization of light at nanoscale interaction lengths. However, their implementation requires surface nanostructuring, based on complex design and fabrication methods. In addition, exploiting narrow spectral features, e.g., for sensing, is accompanied by high demands in terms of precise post‐process alignments of probing light—impractical for compact optical systems. Here, the realization of plasmonic metasurfaces, based on silver nanoparticles (AgNPs) and using a solution‐based growth method, is demonstrated. The particle growth is mediated by localized surface plasmon resonances. The resulting nanostructures are directly applicable as self‐optimized metasurfaces in optical systems, as their fabrication and probing procedures allow the use of common—photonic and plasmonic—platforms. Information regarding the electromagnetic (EM) environment is stored during the fabrication via distinct particle positions and dimensions. The resulting optical response is inherently sensitive to deviations from this EM environment—enabling high‐performance nanoplasmonic sensing with a maximum discrete Figure of Merit* (FoMmax∗ of 968 without the need for post‐process alignments.

Silver nanoparticles (AgNPs) show an extraordinary strong interaction with light, which enables confinement and field enhancement at the nanoscale. However, despite their localized nature, such phenomena are often sought to be exploited on a larger device length scale, for example, in sensors, solar cells, or photocatalytic cells. Unfortunately, this is often limited by strong absorption. One way to reduce these losses is to first focus light with low loss dielectric optics and then to place the AgNPs in that focus. Here, we present a clear experimental proof that growth of AgNPs from the liquid phase at a substrate surface can be controlled by light. Violet light of 405 nm and 1.5 W/cm2 is coupled into thin film resonators and locally focused at their surface. The AgNPs grow at the focus position with sub-Abbe alignment accuracy. Numerical simulations confirm that this alignment causes an increased field enhancement within the AgNPs and is therefore expected to lead to an improved performance of the resulting hybrid devices.

also drawn enormous attention due to their highly tunable electromagnetic proper ties over a broad range of frequencies and novel fields of research such as flatland optics, hyperlenses, and nanoscopic phase manipulation [7][8][9][10][11][12][13][14][15] Especially plasmonic metasurfaces benefit from extraordinary high field intensities, enabling improved absorption of electromagnetic radiation at visible and infrared wavelengths. [16][17][18][19][20] Providing high electrical with thermal con ductivity, plasmonic metamaterial absorbers are therefore promising for various appli cations such as solar energy harves ting, [21,22] heat management, [18] electro thermal systems, [23] sensors [5,17,24] as well as nonlinear optics, [25] and could also serve as electrodes and heat sinks at the same time.In order to achieve absorption in plas monic metasurface-based systems, several methods have been developed. Many of them rely on expensive bottomup processes or need relatively large amounts of metal and/or strongly roughened surfaces in order to obtain broadband absorption. [26][27][28] On the other hand, highly absorbing systems with low material consumption have been realized using dielectric films in order to build metal-insu lator-metal (MIM) absorbers. [9,29,30] Further on, recent MIM absorbers are compatible with costefficient statistical large scale production methods. [31][32][33][34] However, due to the dielectric films, the electrical and thermal conductivity of MIM absorbers are not ideal. If the functionality of MIM absorbers could be preserved without any dielectrics, highly conductive broadband absorbers on large scales with low production costs would be achieved.We present a novel metasurface consisting of only silver, demonstrating the resonant nature of MIM absorbers without the necessity of any insulating spacer material. The technique is performed by polydimethylsiloxane (PDMS)assisted transfer printing of silver nanoparticles (AgNP) directly on top of a thin continuous silver (Ag) film, thus forming a metasurface. In addition to that, the technique can easily be used for costefficient, largearea fabrication on arbitrary substrates. The development of the metasurface is based on the experimental observation, that the absorption of AgNP films on PDMS is significantly enhanced, when they are brought into contact with a silver thin film. Results and Discussion Preliminary Simulation of Simplified GeometriesWe first study this phenomenon with numerical simula tions, whereby AgNPs are approximated by perfect silver In various applications simultaneous large optical absorption and large thermal and electrical conductivity are desired. As bulk materials cannot fulfill that need, metamaterials have been developed that often require complicated nanotechnology. The work presents the facile fabrication of black metasurfaces consisting of silver only. Silver nanoparticles (AgNPs) are transfer printed onto a silver film from a polydimethylsiloxane (PDMS) stamp. Numerical simulations confirm that gap plasmon modes b...