Metasurfaces provide opportunities for wavefront control, flat optics, and subwavelength light focusing. We developed an imaging-based nanophotonic method detecting mid-infrared molecular fingerprints implemented it the chemical identification compositional analysis of surface-bound analytes. Our technique features a two-dimensional pixelated dielectric metasurface with range ultrasharp resonances, each tuned to discrete frequency; this enables absorption signatures be read out at multiple...

A switchable perfect absorber with multispectral thermal imaging capability is presented. Aluminum nanoantenna arrays above a germanium antimony telluride (GST) spacer layer and aluminum mirror provide efficient wavelength-tunable absorption in the mid-infrared. Utilizing amorphous-to-crystalline phase transition GST, this device offers strong reflectance contrast at resonance large phase-change-induced spectral shifts.

Infrared spectroscopy resolves the structure of molecules by detecting their characteristic vibrational fingerprints. Subwavelength light confinement and nanophotonic enhancement have extended scope this technique for monolayer studies. However, current approaches still require complex spectroscopic equipment or tunable sources. Here, we introduce a novel metasurface-based method molecular absorption fingerprints over broad spectrum, which combines device-level simplicity state-of-the-art...

We report on the experimental realization of a palladium-based plasmonic perfect absorber at visible wavelengths and its application to hydrogen sensing. Our design exhibits reflectance <0.5% zero transmittance 650 nm operation wavelength can be tuned by varying structural parameters. Exposure gas causes rapid reversible increase in time scale seconds. This pronounced response introduces novel optical detection scheme with very high values relative intensity response.

Active control over the handedness of a chiral metamaterial has potential to serve as key element for highly integrated polarization engineering approaches, sensitive imaging devices, and stereo display technologies. However, this is hard achieve it seemingly involves reconfiguration metamolecule from left-handed into right-handed enantiomer vice versa. This type mechanical actuation intricate usually neither monolithically realizable nor viable high-speed applications. Here, enabled by...

Abstract A multitude of biological processes are enabled by complex interactions between lipid membranes and proteins. To understand such dynamic processes, it is crucial to differentiate the constituent biomolecular species track their individual time evolution without invasive labels. Here, we present a label-free mid-infrared biosensor capable distinguishing multiple analytes in heterogeneous samples with high sensitivity. Our technology leverages multi-resonant metasurface simultaneously...

Abstract Low‐loss nanostructured dielectric metasurfaces have emerged as a breakthrough platform for ultrathin optics and cutting‐edge photonic applications, including beam shaping, focusing, holography. However, the static nature of their constituent materials has traditionally limited them to fixed functionalities. Tunable all‐dielectric infrared Huygens' consisting multi‐layer Ge disk meta‐units with strategically incorporated non‐volatile phase change material 3 Sb 2 Te 6 are introduced....

Abstract Metasurfaces based on quasi‐bound states in the continuum (quasi‐BICs) constitute an emerging toolkit nanophotonic sensing as they sustain high quality factor resonances and substantial near‐field enhancements. It is demonstrated that silicon metasurfaces composed of crescent shaped meta‐atoms provide tailored light‐matter interaction controlled by geometry. Significantly, this metasurface not only exhibits a fundamental quasi‐BIC resonance, but also supports higher‐order resonance...

Photonic bound states in the continuum (BICs) provide a standout platform for strong light-matter coupling with transition metal dichalcogenides (TMDCs) but have so far mostly been implemented as traditional all-dielectric metasurfaces adjacent TMDC layers, incurring limitations related to strain, mode overlap and material integration. Here, we demonstrate intrinsic BIC-driven composed of nanostructured bulk tungsten disulfide (WS2) exhibiting resonances sharp, tailored linewidths selective...

Plasmon resonances play a pivotal role in enhancing light-matter interactions nanophotonics, but their low-quality factors have hindered applications demanding high spectral selectivity. Here, we demonstrate the design and 3D laser nanoprinting of plasmonic nanofin metasurfaces, which support symmetry-protected bound states continuum up to fourth order. By breaking nanofins’ out-of-plane symmetry parameter space, achieve high-quality factor (up 180) modes under normal incidence. The can be...

Abstract The realization of lossless metasurfaces with true chirality crucially requires the fabrication three-dimensional structures, constraining experimental feasibility and hampering practical implementations. Even though assembly metallic nanostructures has been demonstrated previously, resulting plasmonic resonances suffer from high intrinsic radiative losses. concept photonic bound states in continuum (BICs) is instrumental for tailoring losses diverse geometries, especially when...

All-dielectric nanophotonics underpinned by the physics of bound states in continuum (BICs) have demonstrated breakthrough applications nanoscale light manipulation, frequency conversion and optical sensing. Leading BIC implementations range from isolated nanoantennas with localized electromagnetic fields to symmetry-protected metasurfaces controllable resonance quality (Q) factors. However, they either require structured illumination complex beam-shaping optics or large, fabrication-intense...

Abstract To control and enhance light–matter interactions at the nanoscale, two parameters are central: spectral overlap between an optical cavity mode material’s features (for example, excitonic or molecular absorption lines), quality factor of cavity. Controlling both simultaneously would enable investigation systems with complex features, such as multicomponent mixtures heterogeneous solid-state materials. So far, it has been possible only to sample a limited set data points within this...

Investigating new materials plays an important role for advancing the field of nanoplasmonics. In this work, we fabricate nanodisks from magnesium and demonstrate tuning their plasmon resonance throughout whole visible wavelength range by changing disk diameter. Furthermore, employ a catalytic palladium cap layer to transform metallic Mg particles into dielectric MgH2 when exposed hydrogen gas. We prove that transition can be reversed in presence oxygen. This yields plasmonic nanostructures...

Graphene is emerging as a promising material for photonic applications owing to its unique optoelectronic properties. supports tunable, long-lived and extremely confined plasmons that have great potential such biosensing optical communications. However, in order excite plasmonic resonances graphene, this requires high doping level, which challenging achieve without degrading carrier mobility stability. Here, we demonstrate the infrared response of graphene multilayer stack analogous highly...

Detection and differentiation of enantiomers in small quantities are crucially important many scientific fields, including biology, chemistry, pharmacy. Chiral molecules manifest their handedness interaction with the chiral state light (e.g., circularly polarized light), which is commonly leveraged circular dichroism (CD) spectroscopy. However, compared to linear refractive index molecular chirality extremely weak, resulting low detection efficiencies. Recently, it has been shown that these...

Plasmonic devices with absorbance close to unity have emerged as essential building blocks for a multitude of technological applications ranging from trace gas detection infrared imaging. A crucial requirement such elements is the angle independence absorptive performance. In this work, we develop theoretically and verify experimentally quantitative model angular behavior plasmonic perfect absorber structures based on an optical impedance matching picture. To achieve this, utilize simple...

Abstract Sensitive and robust detection of gases chemical reactions constitutes a cornerstone scientific research key industrial applications. In an effort to reach progressively smaller reagent concentrations sensing volumes, optical sensor technology has experienced paradigm shift from extended thin-film systems towards engineered nanoscale devices. this size regime, plasmonic particles nanostructures provide ideal toolkit for the realization novel concepts. This is due their unique...

Locally probing chemical reactions or catalytic processes on surfaces under realistic reaction conditions has remained one of the main challenges in materials science and heterogeneous catalysis. Where conventional surface interrogation techniques usually require high-vacuum ensemble average measurements, plasmonic nanoparticles excel extreme light focusing can produce highly confined electromagnetic fields subwavelength volumes without need for complex near-field microscopes. Here, we...

Abstract All-dielectric metasurfaces supporting photonic bound states in the continuum (BICs) are an exciting toolkit for achieving resonances with ultranarrow linewidths. However, transition from theory to experimental realization can significantly reduce optical performance of BIC-based nanophotonic systems, severely limiting their application potential. Here, we introduce a combined numerical/experimental methodology predicting how unavoidable tolerances nanofabrication such as random...

Abstract Optofluidic sensors integrate photonics with micro/nanofluidics to realize compact devices for the label‐free detection of molecules and real‐time monitoring dynamic surface binding events high specificity, ultrahigh sensitivity, low limit, multiplexing capability. Nanophotonic structures composed metallic and/or dielectric building blocks excel at focusing light into ultrasmall volumes, creating enhanced electromagnetic near‐fields ideal amplifying molecular signal readout....