Abstract: Supercoupling waveguides are provided in which acoustic impedance at an acoustic input port matches the acoustic impedance at an acoustic output port, where the acoustic path extending from the acoustic input port to the acoustic output port has a variable length. The supercoupling waveguides may be used in methods of sensing and measuring, and may be incorporated into sensors.

Abstract: The disclosed matter provides integrated metasurface devices for conversion between a waveguide mode and a free-space optical wave with a designer wavefront. In exemplary embodiments, the integrated metasurface devices include a thin waveguide, a waveguide taper, a leaky-wave metasurface defined within a high refractive index layer of dielectric material, and a low refractive index substrate. The device can manipulate all the four optical degrees of freedom of the free-space wavefront, namely: amplitude, phase, polarization orientation, and polarization ellipticity, by using a leaky-wave metasurface composed of meta-units with four structural degrees of freedom.

Abstract: An optical combiner includes a first layer with a periodic two-dimensional arrangement of structures arranged to support resonance for an input signal of a target wavelength, wherein the structures have a first refractive index. A second layer overlies the structures on the first layer, wherein the second layer includes a second material with a second refractive index, and wherein a difference between the first refractive index and the second refractive index, measured at 587.5 nm, is less than about 1.5. The periodic arrangement of structures is configured such that the optical combiner produces, for the input signal incident on the first layer from air at an oblique elevation angle of greater than about 20°, an output signal with a reflection peak with an average reflection of greater than about 50% within a ± 5° range of the elevation angle.

Abstract: An optical combiner includes a first layer with a periodic arrangement of structures of a material with a first refractive index. A second layer overlies the structures on the first layer, and the second layer includes a material with a second refractive index. A difference between the first refractive index and the second refractive index, measured at 587.5 nm, is less than 1.5. The periodic arrangement of structures is configured such that the optical combiner produces, for an input signal incident on the first layer from air at an oblique elevation angle of greater than 20°, an output signal with three reflection peaks, each reflection peak having an average reflection of greater than 50% within a ±3° range of the elevation angle.

Abstract: Supercoupling waveguides are provided in which acoustic impedance at an acoustic input port matches the acoustic impedance at an acoustic output port, where the acoustic path extending from the acoustic input port to the acoustic output port has a variable length. The supercoupling waveguides may be used in methods of sensing and measuring, and may be incorporated into sensors.

Abstract: A thermal metasurface that provides a planar optical source based on thermal radiation or photoluminescence. The thermal metasurface provides dual perturbative control of both radiative and non-radiative lifetimes of a q-BIC via geometric and material perturbation of monomeric and dimeric pillars.

Abstract: A metasurface that is designed to control electromagnetic radiation (EMR) in ways that perform more than a single function. The metasurface has a substrate layer that has multiple asymmetric nanofeatures, each having a height (H) between ?min/100 and 2?max. Each nanofeature has a particular length (Dy) that extends along a principal in-plane direction ? and a width (Dx) that is orthogonal thereto. Each nanofeature is tailored to scatter with different patterns one polarization state of electromagnetic radiation and one orthogonal polarization state of electromagnetic radiation.

Abstract: Supercoupling power dividers are provided, in which acoustic impedance at an acoustic input port matches the combined acoustic impedance at two or more acoustic output ports, and the phase of the input signal matches the combined phases of the two or more acoustic output ports. Methods for achieving impedance matching using a uniform-phase acoustic power divider are also provided. The devices and methods achieve acoustic supercoupling without requiring embedded membranes or resonators.

Abstract: A magnet-free non-reciprocal device realized using modulated filters. The device includes one or more filters in one or more branches, where each branch connects two ports or a port and a central node. The poles and zeros of each of the first, second and third filters are modulated in time such that degenerate modes at each pole and zero is split thereby destructively interfering at one or more output ports and adding up at another output port allowing non-reciprocal transmission, isolation and/or non-reciprocal phase shift. The device is able to realize a magnet-free full-duplex communication scheme implementing a magnet-free circulator for radio frequency cancellation or a magnet-free isolator or gyrator.

Abstract: A microelectromechanical resonant circulator device is providing, having a substrate, and at least three electrical ports supported on the substrate. At least three electromechanical resonator elements are connected with associated switch elements and an associated port. The switch elements are operative to provide commutation over time of the electromechanical resonator elements.

Abstract: A magnet-free non-reciprocal device realized using modulated filters. The device includes one or more filters in one or more branches, where each branch connects two ports or a port and a central node. The poles and zeros of each of the first, second and third filters are modulated in time such that degenerate modes at each pole and zero is split thereby destructively interfering at one or more output ports and adding up at another output port allowing non-reciprocal transmission, isolation and/or non-reciprocal phase shift. The device is able to realize a magnet-free full-duplex communication scheme implementing a magnet-free circulator for radio frequency cancellation or a magnet-free isolator or gyrator.

Abstract: A microelectromechanical resonant circulator device is providing, having a substrate, and at least three electrical ports supported on the substrate. At least three electromechanical resonator elements are connected with associated switch elements and an associated port. The switch elements are operative to provide commutation over time of the electromechanical resonator elements.

Abstract: A communication system that reduces the mutual influence of antennas operating in similar or different frequency bands. The communication system includes a first and a second antenna operating in a first and a second frequency band, respectively, and placed in close proximity to each other. The first antenna is covered by a conformal mantle metasurface with anti-phase scattering properties thereby cancelling the scattering in the second frequency band. The conformal mantle metasurface consists of a patterned metallic sheet comprising slits both in an azimuthal and a vertical direction to reduce both vertical and horizontal polarization scattering. When the first antenna is a low-band dipole antenna and when the second antenna is a high-band dipole antenna, the conformal mantle metasurface reduces the low-band blockage without disrupting the performance of both antennas in terms of radiation pattern and impedance matching.

Abstract: A non-reciprocal device using a space-time modulation scheme. By applying the space-time modulation scheme, reciprocity in radiation and scattering scenarios is prevented. Such a scheme utilizes a linear system with simple, compact and inexpensive electronic components compared to the current use of bulky duplexers and non-reciprocal magnet based phase shifters to provide non-reciprocity. One such linear system involves traveling-wave antennas loaded with voltage dependent capacitors that are modulated in space and time thereby allowing the antenna to transmit with high directivity in a certain direction and not receive from that direction. Another linear system involves a resonant metasurface characterized by transverse spatiotemporal gradients, where the spatiotemporal gradients include periodically modulated impedances thereby causing a non-reciprocal transmission response.

Abstract: A non-reciprocal device incorporating metamaterials which exhibit non-reciprocity through angular momentum biasing. The metamaterial, such as a ring resonator, is angular-momentum biased. This is achieved by applying a suitable mechanical or spatio-temporal modulation to resonant inclusions of the metamaterial, thereby producing strong non-reciprocity. In this manner, non-reciprocity can be produced without requiring the use of large and bulky magnets to produce a static magnetic field. The metamaterials of the present invention can be realized by semiconducting and/or metallic materials which are widely used in integrated circuit technology, and therefore, contrary to magneto-optical materials, can be easily integrated into the non-reciprocal devices and large microwave or optical systems. The metamaterials of the present invention can be compact at various frequencies due to the enhanced wave-matter interaction in the constituent resonant inclusions.

Abstract: A transparent dielectric-core antenna surrounded by patterned metallic metasurfaces. The patterned metallic metasurface acts as a conductive medium for surface current to flow and efficiently radiate fields driven by a power source. Furthermore, the patterned metallic metasurface can strongly reduce the electrical presence of the dielectric-core to realize a radio-transparent antenna to nearby systems at any desired frequency band while still maintaining good radiation and matching properties. Such an antenna concept may be applied to a variety of geometries.

Abstract: Described are methods of determining a property of a sample, examples of sample properties that can be determined and provided using the methods described herein include, for example, the chirality of the analyte, the presence of chiral analyte, the circular dichroism of sample, the concentration of the analyte in the sample, or a combination thereof.

Abstract: A non-reciprocal device using a space-time modulation scheme. By applying the space-time modulation scheme, reciprocity in radiation and scattering scenarios is prevented. Such a scheme utilizes a linear system with simple, compact and inexpensive electronic components compared to the current use of bulky duplexers and non-reciprocal magnet based phase shifters to provide non-reciprocity. One such linear system involves traveling-wave antennas loaded with voltage dependent capacitors that are modulated in space and time thereby allowing the antenna to transmit with high directivity in a certain direction and not receive from that direction. Another linear system involves a resonant metasurface characterized by transverse spatiotemporal gradients, where the spatiotemporal gradients include periodically modulated impedances thereby causing a non-reciprocal transmission response.

Abstract: A nonlinear metasurface structure including a multi-quantum-well layer designed for a nonlinear response for a desired nonlinear optical process and an array of nanoantennas coupled to the intersubband transitions of the multi-quantum-well layer. Each nanoantenna in the array is designed to have electromagnetic resonances at or close to all input and output frequencies of a given nonlinear optical process. Nanoantennas allow efficient coupling of any incident and outgoing light polarizations to intersubband transitions. Nanoantennas may further provide significant field enhancement in the multi-quantum-well layer. As a result, the nonlinear metasurface structure can be designed to produce a highly nonlinear response for any polarization and angle of incidence of incoming and outgoing waves in a nonlinear optical process. Due to their very larger nonlinear response, efficient frequency conversion can be produced in these metasurfaces without the stringent phase-matching constraints of bulk nonlinear crystals.

Abstract: A non-reciprocal device incorporating metamaterials which exhibit non-reciprocity through angular momentum biasing. The metamaterial, such as a ring resonator, is angular-momentum biased. This is achieved by applying a suitable mechanical or spatio-temporal modulation to resonant inclusions of the metamaterial, thereby producing strong non-reciprocity. In this manner, non-reciprocity can be produced without requiring the use of large and bulky magnets to produce a static magnetic field. The metamaterials of the present invention can be realized by semiconducting and/or metallic materials which are widely used in integrated circuit technology, and therefore, contrary to magneto-optical materials, can be easily integrated into the non-reciprocal devices and large microwave or optical systems. The metamaterials of the present invention can be compact at various frequencies due to the enhanced wave-matter interaction in the constituent resonant inclusions.