Abstract: A multi-wavelength laser apparatus is provided. The multi-wavelength laser apparatus may include a meta-mirror layer having a surface in which a plurality of patterns are formed, a laser emitter disposed on the meta-mirror layer, and an upper-mirror layer disposed on the laser emitter. The multi-wavelength laser apparatus may further include a conductive graphene layer between the meta-mirror layer and the laser emitter.

Abstract: Embodiments of 3D imaging systems that use a multifunctional, nano structured metalens to replace the conventional microlens array in light field imaging are disclosed. The optical focusing properties of the metalenses provided by gradient metasurface optical elements. The gradient metasurfaces allow the properties of the elements of the metalens array to be changed by tuning the gradient metasurfaces.

Abstract: A laser beam steering system is disclosed. The system includes a laser source which produces a pulsed laser light beam with a frequency comb spectrum, a metasurface configured to i) receive the pulsed laser, ii) generate a diffracted pulsed laser output at different frequencies with a beam at a center frequency normal to the metasurface, and iii) directing light at different frequencies onto different foci at a focal plane, light propagating from the focal plane leads to generation of one or more optical beams that are controlled in space and time.

Abstract: Provided are a diffraction grating device, a method of manufacturing the diffraction grating device, and an optical apparatus including the diffraction grating device. The diffraction grating device includes a diffraction grating arranged on a light reflection substrate. The diffraction grating includes a plurality of diffraction elements, each diffraction element from among the plurality of diffraction elements having a height that causes a destructive interference between first light rays reflected by a top surface therefore and second light rays reflected by a bottom surface thereof, the first and second light rays being incident on the top and bottom surfaces, respectively, at an incidence angle greater than 45°.

Abstract: Waveguide enhanced resonant diffraction is provided in grating structures having negligible non-resonant diffraction by the grating. This is done by making the grating thickness much less than any relevant wavelength, and by having the grating in proximity to a waveguide for diffractive coupling to and from a mode of the waveguide. Material absorption in the grating material can be used to suppress undesired diffraction orders. The resulting structures can provide rainbow-free diffractive optical sampling.

Abstract: A multi-stack graphene structure includes a graphene stack that includes graphene layers including amorphous graphene and thin film dielectric layers. The graphene layers include amorphous graphene. The graphene layers and the thin dielectric layers are alternately stacked on one another. The multi-stack graphene structure also includes an electric field former configured to apply an electric field to the graphene layers.

Abstract: A light emitting device including a micro cavity having a phase modulation surface and a display apparatus including the light emitting device are provided. The light emitting device includes a reflective layer including a phase modulation surface; a first electrode disposed on the phase modulation surface of the reflective layer; a light emitting structure disposed on the first electrode; and a second electrode disposed on the light emitting structure. The phase modulation surface may include a plurality of nano scale patterns that are regularly or irregularly arranged. The reflective layer and the second electrode may constitute the micro cavity having a resonance wavelength of the light emitting device.

Abstract: A beam steering method and device are provided. The beam steering method includes outputting, from a hologram recording medium on which a plurality of signal light beams having different steering information are recorded, signal light beam having specific steering information, by making reference light having a specific characteristic incident on the hologram recording medium. The method further includes o obtaining information about an object existing in the external environment based on the output signal light.

Abstract: A multifunctional dielectric gradient metasurface optical device has a layer of nanoscale dielectric gradient metasurface optical antenna elements deposited on a substrate layer, arranged with spatially varying orientations, shapes, or sizes in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The spatially varying optical phase response is a spatial interleaving of multiple distinct phase profiles corresponding to multiple optical sub-elements, thereby providing multifunctional wavefront shaping in the single optical element.

Abstract: A multi-wavelength laser apparatus is provided. The multi-wavelength laser apparatus may include a meta-mirror layer having a surface in which a plurality of patterns are formed, a laser emitter disposed on the meta-mirror layer, and an upper-mirror layer disposed on the laser emitter. The multi-wavelength laser apparatus may further include a conductive graphene layer between the meta-mirror layer and the laser emitter.

Abstract: An optical device and an optical system including the optical device are provided. The optical device may include a reflective layer and a plurality of nano-beams spaced apart from the reflective layer. The plurality of nano-beams may be formed as a metasurface. The nano-beams may have a pattern structure having a plurality of metasurface forms, and the distance of the gaps between the plurality of nano-beams and the reflective layer may be adjustable individually or as a whole. The optical device may be a beam steering device or an optical phase modulator.

Abstract: A monolithic optical device for light manipulation and control at visible wavelengths includes a device layer deposited on an sacrificial layer deposited on a reflective substrate. The device layer comprises an elastic support structure and nanoscale optical antenna elements, arranged such that the nanoscale optical antenna elements are capable of moving vertically in response to application of an electrostatic potential between the device layer and the reflective substrate. The sacrificial layer joins the elastic support structure to the reflective substrate. The reflective substrate is reflective at optical wavelengths.

Abstract: Patterning planar photo-absorbing materials into arrays of nanowires is demonstrated as a method for increasing the total photon absorption in a given thickness of absorbing material. Such a method can provide faster, cheaper, and more efficient photo-detectors and solar cells. A thin nanowire can absorb many more photons than expected from the size of the nanowire. The reason for this effect is that such nanowires support cylindrical particle resonances which can collect photons from an area larger than the physical cross-section of the wire. These resonances are sometimes referred to as Mie resonances or Leaky Mode Resonances (LMRs). The nanowires can have various cross section shapes, such as square, circle, rectangle, triangle, etc.

Abstract: A multi-stack graphene structure includes a graphene stack that includes graphene layers including amorphous graphene and thin film dielectric layers. The graphene layers include amorphous graphene. The graphene layers and the thin dielectric layers are alternately stacked on one another. The multi-stack graphene structure also includes an electric field former configured to apply an electric field to the graphene layers.

Abstract: A multifunctional dielectric gradient metasurface optical device has a layer of nanoscale dielectric gradient metasurface optical antenna elements deposited on a substrate layer, arranged with spatially varying orientations, shapes, or sizes in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The spatially varying optical phase response is a spatial interleaving of multiple distinct phase profiles corresponding to multiple optical sub-elements, thereby providing multifunctional wavefront shaping in the single optical element.

Abstract: Embodiments of 3D imaging systems that use a multifunctional, nano structured metalens to replace the conventional microlens array in light field imaging are disclosed. The optical focusing properties of the metalenses provided by gradient metasurface optical elements. The gradient metasurfaces allow the properties of the elements of the metalens array to be changed by tuning the gradient metasurfaces.

Abstract: A dielectric gradient metasurface optical device provides optical wavefront shaping using an ultrathin (less than 100 nm thick) layer of nanoscale geometric Pancharatnam-Berry phase optical elements deposited on a substrate layer. The optical elements are nanobeams composed of high refractive index dielectric material. The nanobeams have uniform size and shape and are arranged with less than 200 nm separations and spatially varying orientations in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The high refractive index dielectric material may be materials compatible with semiconductor electronic fabrication, including silicon, polysilicon, germanium, gallium arsenide, titanium dioxide, or iron oxide.

Abstract: A dielectric gradient metasurface optical device provides optical wavefront shaping using an ultrathin (less than 100 nm thick) layer of nanoscale geometric Pancharatnam-Berry phase optical elements deposited on a substrate layer. The optical elements are nanobeams composed of high refractive index dielectric material. The nanobeams have uniform size and shape and are arranged with less than 200 nm separations and spatially varying orientations in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The high refractive index dielectric material may be materials compatible with semiconductor electronic fabrication, including silicon, polysilicon, germanium, gallium arsenide, titanium dioxide, or iron oxide.

Abstract: Patterning planar photo-absorbing materials into arrays of nanowires is demonstrated as a method for increasing the total photon absorption in a given thickness of absorbing material. Such a method can provide faster, cheaper, and more efficient photo-detectors and solar cells. A thin nanowire can absorb many more photons than expected from the size of the nanowire. The reason for this effect is that such nanowires support cylindrical particle resonances which can collect photons from an area larger than the physical cross-section of the wire. These resonances are sometimes referred to as Mie resonances or Leaky Mode Resonances (LMRs). The nanowires can have various cross section shapes, such as square, circle, rectangle, triangle, etc.

Abstract: Aspects of the present disclosure are directed to apparatuses and methods involving nanowires having junctions therebetween. As consistent with one or more embodiments, an apparatus includes first and second sets of nanowires, in which the second set overlaps the first set. The apparatus further includes a plurality of nanowire joining recrystallization junctions, each junction including material from a nanowire of the first set that is recrystallized into an overlapping nanowire of the second set.