Abstract: In certain examples, methods and semiconductor structures, aspects of the disclosure are directed to a guided-mode resonance metasurface pixel (“GMR pixel”) having a cavity section to support GMR at a certain Q and having optics at each end of the GMR pixel, to contain light and mitigate energy losses due to scattering of light, in response to light being directed towards the GMR pixel of the metasurface sensor. In certain more-specific examples, exemplary aspects of the disclosure are directed to a functionalized metasurface sensor including an array of guided-mode resonance metasurface biosensor pixels, each of which is functionalized for attachment of a distinct receptor or probe molecules.

Abstract: A device for detecting optical chirality includes a metasurface composed of a biperiodic array of nanodisks in the form of a checkerboard array [300], where the nanodisks have diameters d±?/2 such that adjacent nanodisks [302, 304] have diameters that differ by an offset ?. The nanodisks are composed of a dielectric material that is transparent and has a refractive index greater than 2 at a predetermined operational ultraviolet wavelength. The nanodisks have a width-to-height aspect ratio d/h tuned to produce spectral overlap of electric dipole and magnetic dipole modes of incident circularly polarized ultraviolet light.

Abstract: Systems and methods for compact and low-cost vibrational spectroscopy platforms are described. Many embodiments implement deep learning processes to identify the relevant optical spectral features for the identification of an element from a set of elements. Several embodiments provide that resolution reduction and feature selection render efficient data analysis processes. By reducing the spectral data from the full wide-band high-resolution spectrum to a subset of spectral bands, a number of embodiments provide compact and low-cost hardware incorporation in spectroscopic platforms for element identification functions.

Abstract: Improved stimulated Raman spectroscopy is provided by replacing the Stokes (or anti-Stokes) optical source with a localized electromagnetic emitter that is excited with a non-electromagnetic excitation. Such a localized emitter can be an efficient Stokes (or anti-Stokes) source for stimulated Raman spectroscopy, and can also provide deep sub-wavelength spatial resolution. In a preferred embodiment, an electron beam from an electron microscope is used to excite the localized emitter. This provides combined Raman imaging and electron microscopy that has the two imaging modalities inherently registered with each other.

Abstract: Improved photocatalysis is provided for chemical reactions involving hydrogen in two component plasmon-catalyst nanoparticles. The main idea of this work is to configure the optical illumination of the nano-articles to suppress formation of an undesirable hydride phase in the nanoparticles. This idea is broadly applicable to any chemical reaction involving hydrogen. Specific examples considered experimentally in this work are acetylene hydrogenation to produce ethylene, carbon dioxide reduction and ammonia synthesis.

Abstract: We utilize high-quality-factor (high-Q) metasurfaces patterned either in or adjacent to electro-optical or thermo-optical materials such as lithium niobate, barium titanate, or thermally-sensitive polymers. The metasurface includes nanoantennas that act as dipole emitters; the particular structure and arrangement of nanoantennas can steer light to particular directions or focus light, The electromagnetic metasurface supports one or more guided mode resonances. The metasurface also includes a perturbation superposed on the metasurface features and configured to couple free-space radiation to the guided mode resonances.

Abstract: Optical sensing of biological targets is provided using a metasurface having guided mode resonances with electric field profiles that extend out from the metasurface. Surface functionalization of such metasurfaces can be used to provide sensing for biological targets, such as nucleic acids, proteins, small molecules, extracellular vesicles, and whole cells. Binding of the target to the surface functionalization can affect the resonance wavelength of the guided mode resonances, thereby providing a sensitive assay for the biological targets.

Abstract: Improved surface enhanced Raman spectroscopy (SERS) of biological targets in liquids is provided. Nanoparticles are treated with a surfactant to provide an electrostatic attraction between the nanoparticles and the biological targets. The resulting clustering of the nanoparticles at the biological targets improves the SERS signal, Such SERS spectroscopy enables real time monitoring of the biological targets, thereby enabling a wide variety of assays etc.

Abstract: Self-isolated lasers are provided by using a chiral metasurface in combination with a spin-selective gain medium and symmetry-breaking (i.e., not linearly polarized) optical pumping. In preferred embodiments the chiral metasurface is resonant, thereby proving an integrated optical resonator to support lasing. The chiral metasurface can be the spin-selective gain medium, or it can be formed on a surface of the spin-selective gain medium, or it can be distinct from the spin-selective gain medium.

Abstract: Methods to detect contaminants in a solution and applications thereof are described. Generally, solutions are printed onto a substrate and then imaged via Raman spectroscopy, which can be utilized to detect signals derived from contaminants.

Abstract: A device for detecting optical chirality includes a metasurface composed of a biperiodic array of nanodisks in the form of a checkerboard array [300], where the nanodisks have diameters d±?/2 such that adjacent nanodisks [302, 304] have diameters that differ by an offset ?. The nanodisks are composed of a dielectric material that is transparent and has a refractive index greater than 2 at a predetermined operational ultraviolet wavelength. The nanodisks have a width-to-height aspect ratio d/h tuned to produce spectral overlap of electric dipole and magnetic dipole modes of incident circularly polarized ultraviolet light.

Abstract: A metasurface optical device composed of three stacked dielectric layers which form an anti-reflective structure for wavelengths in a predetermined operational wavelength range within the visible spectrum. The anti-reflective structure contains a rectangular lattice of rhombohedral perturbations that produce guided-mode resonances within the predetermined operational wavelength range. The guided-mode-resonant dielectric metasurface device is capable of detecting by colorimetric readout the presence and orientation of a linearly birefringent anisotropic medium, such as a fibrous tissue, positioned above the stacked dielectric layers.

Abstract: Improved stimulated Raman spectroscopy is provided by replacing the Stokes (or anti-Stokes) optical source with a localized electromagnetic emitter that is excited with a non-electromagnetic excitation. Such a localized emitter can be an efficient Stokes (or anti-Stokes) source for stimulated Raman spectroscopy, and can also provide deep sub-wavelength spatial resolution. In a preferred embodiment, an electron beam from an electron microscope is used to excite the localized emitter. This provides combined Raman imaging and electron microscopy that has the two imaging modalities inherently registered with each other.

Abstract: High quality factor electromagnetic metasurfaces are provided. The metasurface is configured to have in plane guided-mode resonances (e.g., corresponding to waveguide modes or the like). Coupling features are included in the metasurface that are configured to couple free-space radiation to the guided mode resonances. The resulting structures have a high-Q response to free-space radiation and can be used for various applications, such as beam splitting, beam steering, and beam focusing or defocusing.

Abstract: High quality factor electromagnetic metasurfaces are provided. The metasurface is configured to have in plane guided-mode resonances (e.g., corresponding to waveguide modes or the like). Coupling features are included in the metasurface that are configured to couple free-space radiation to the guided mode resonances. The resulting structures have a high-Q response to free-space radiation and can be used for various applications, such as beam splitting, beam steering, and beam focusing or defocusing.

Abstract: Quantum converting nanoparticles for electric field sensing are provided. In one example, by combining upconverting lanthanide ions with voltage responsive dyes, we generate an optical platform that displays intensity and spectrum changes in the presence of electric fields. Our particles enable local (down to 10 nm spatial resolution) mapping of electric fields with exceptional photostability. We can image and quantify in vivo and in situ electric fields in biological and material systems up to fields of ˜100 kV/cm.

Abstract: A metasurface optical device composed of three stacked dielectric layers which form an anti-reflective structure for wavelengths in a predetermined operational wavelength range within the visible spectrum. The anti-reflective structure contains a rectangular lattice of rhombohedral perturbations that produce guided-mode resonances within the predetermined operational wavelength range. The guided-mode-resonant dielectric metasurface device is capable of detecting by colorimetric readout the presence and orientation of a linearly birefringent anisotropic medium, such as a fibrous tissue, positioned above the stacked dielectric layers.

Abstract: In one aspect, a cathodoluminescence (CL) spectroscopic tomography device includes a sample stage to support a sample. An electron beam source scans an electron beam over the sample to yield light emission by the sample. A reflective element directs the light emission by the sample to a light detector. A controller controls operation of the sample stage, the electron beam source, and the light detector. In one aspect, a CL spectroscopic tomography device includes an electron beam source which directs an electron beam at an object to yield an emission by the object. A detector detects the emission. A controller receives information from the detector related to the detected emission. The controller derives a two-dimensional (2D) CL map from the information related to the detected emission, and derives a three-dimensional (3D) CL tomogram from the 2D CL map.

Abstract: A device includes a light adjustment apparatus having at least one material having a dielectric permittivity, the at least one material to affect the flow of light, wherein the light adjustment apparatus includes a tunable material to enable adjustment of the dielectric permittivity of the at least one material.

Abstract: Quantum converting nanoparticles for electric field sensing are provided. In one example, by combining upconverting lanthanide ions with voltage responsive dyes, we generate an optical platform that displays intensity and spectrum changes in the presence of electric fields. Our particles enable local (down to 10 nm spatial resolution) mapping of electric fields with exceptional photostability. We can image and quantify in vivo and in situ electric fields in biological and material systems up to fields of ˜100 kV/cm.