Abstract: Systems, devices, and techniques for performing wavelength division multiplexing or demultiplexing using one or more metamaterials in an optical communications systems are described. An optical device may be configured to shift one or more phase profiles of an optical signal using one or more stages of metamaterials to multiplex or demultiplex wavelengths of optical signals. The optical device may be an example of a stacked design with two or more stages of metamaterials stacked on top of one another. The optical device may be an example of a folded design that reflects optical signals between different stages of metamaterials.

Abstract: Metasurface optical components deposited on the surface of a substrate are used to provide dispersive phase compensation alter incident light. The metasurface optical components comprise a pattern of silicon dielectric resonators that have nonperiodic gap distances between adjacent silicon dielectric resonators; and each silicon dielectric resonator is an elongated rectangular prism that has a width that is distinct from the width of other dielectric resonators, a length, and a thickness. Incident multi-wavelength light is directed to the metasurface optical components, wherein the nonperiodicity of the gap distances and the distinct widths, and the thicknesses are engineered to deflect a plurality of wavelengths of interest from the incident multi-wavelength light at a plurality of deflection angles configured to scatter the incident light and impart a phase shift, ranging at least from 0 to 2?, on an outgoing light.

Abstract: An optical communication system can include a multiplexer/demultiplexer. The multiplexer/demultiplexer can transfer a first optical data signal between a first single-mode fiber and a first propagation mode of a few-mode fiber. The first propagation mode can have a first effective refractive index. The multiplexer/demultiplexer can transfer a second optical data signal between a second single-mode fiber and a combination of a second propagation mode of the few-mode fiber and a third propagation mode of the few-mode fiber. The second propagation mode and the third propagation mode can have a same effective refractive index that differs from the first effective refractive index. During propagation within the few-mode fiber, the second optical data signal can couple bidirectionally between the second propagation mode and the third propagation mode, while being substantially isolated from the first optical data signal in the first propagation mode.

Abstract: Metasurface optical components deposited on the surface of a substrate are used to alter incident light. The metasurface optical components comprise a pattern of silicon dielectric resonators that have nonperiodic gap distances between adjacent silicon dielectric resonators; and each silicon dielectric resonator is an elongated rectangular prism that has a width, a length, and a thickness. Incident light is directed to the metasurface optical components, wherein the gap distances, the widths, and the thicknesses are configured to scatter the incident light and impart a phase shift, ranging at least from 0 to 2?, on an outgoing light. Each dielectric resonator has a rectangular cross-section in a plane perpendicular to the substrate surface such that a first phase shift is imparted for a transverse-electric (TE) component of the incident light and a second phase shift is imparted for a transverse-magnetic (TM) component of the incident light.

Abstract: An optical device includes a membrane. The membrane includes a plurality of apertures extending at least partially through a thickness of the membrane. The membrane is configured to structure incoming light having a wavelength to produce modified light. The wavelength of the incoming light is in a range of a wavelength of X-ray light to a wavelength of ultraviolet light. The membrane can be configured to transmit the modified light through the membrane. The membrane can be configured to reflect modified light away from the membrane. An index of refraction within a first aperture of the plurality of apertures is greater than an index of refraction of the membrane.

Abstract: A device includes a first mode converter and a second mode converter that define a region between the first mode converter and the second mode converter. The region can contain a plurality of orthogonal modes of a wave. The wave, when sent from outside the region and when propagating from the first mode converter towards the second mode converter, can include a first mode of the plurality of orthogonal modes. The second mode converter can convert the wave from the first mode of the plurality of orthogonal modes, to a second mode of the plurality of orthogonal modes that is different from the first mode. The first mode converter can convert the wave to the first mode of the plurality of orthogonal modes.

Abstract: Disclosed is a depth sensor for determining depth. The depth sensor can include a photosensor, a metalens configured to manipulate light to simultaneously produce at least two images having different focal distances on a surface of the photosensor, and processing circuitry configured to receive, from the photosensor, a measurement of the at least two images having different focal distances. The depth sensor can determine, according to the measurement, a depth associated with at least one feature in the at least two images.

Abstract: An endoscopic imaging device (e.g., a catheter) comprises a light-transmitting tubing, at least one optical fiber disposed in the light-transmitting tubing, and at least one metalens. The metalens is optically coupled to the optical fiber and is configured to focus light from the optical fiber, through the light-transmitting tubing, and to a target point located outside of the light-transmitting tubing. The metalens includes a plurality of nanostructures. The nanostructures define a phase profile that corrects astigmatism caused by the light-transmitting tubing.

Abstract: Disclosed is a depth sensor for determining depth. The depth sensor can include a photosensor, a metalens configured to manipulate light to simultaneously produce at least two images having different focal distances on a surface of the photosensor, and processing circuitry configured to receive, from the photosensor, a measurement of the at least two images having different focal distances. The depth sensor can determine, according to the measurement, a depth associated with at least one feature in the at least two images.

Abstract: The present disclosure provides an optical component, which may be a metasurface grating, including (a) a substrate; and (b) an array of subwavelength-spaced phase-shifting elements, which are tessellated on the substrate to produce, when illuminated with a polarized incident light, a diffracted light beam with a distinct polarization state for each of a finite number of diffraction orders, wherein the finite number is 2 or more.

Abstract: Systems, devices, and techniques for performing wavelength division multiplexing or demultiplexing using one or more metamaterials in an optical communications systems are described. An optical device may be configured to shift one or more phase profiles of an optical signal using one or more stages of metamaterials to multiplex or demultiplex wavelengths of optical signals. The optical device may be an example of a stacked design with two or more stages of metamaterials stacked on top of one another. The optical device may be an example of a folded design that reflects optical signals between different stages of metamaterials.

Abstract: An optical device comprises a metasurface including a plurality of nanostructures. The nanostructures convert an input light of an arbitrary spin state into an output light of an arbitrary total angular momentum state characterized by a superposition of two independent orbital angular momentum (OAM) states.

Abstract: An optical metasurface film includes a flexible polymeric film having a first major surface, a patterned polymer layer having a first surface proximate to the first major surface of the flexible polymeric film and having a second nanostructured surface opposite the first surface, and a refractive index contrast layer adjacent to the nanostructured surface of the patterned polymer layer forming a nanostructured bilayer with a nanostructured interface. The nanostructured bilayer acts locally on amplitude, phase, or polarization of light, or a combination thereof and imparts a light phase shift that varies as a function of position of the nano structured bilayer on the flexible polymeric film. The light phase shift of the nanostructured bilayer defines a predetermined operative phase profile of the optical metasurface film.

Abstract: Polarization-insensitive metasurfaces using anisotropic nanostructures are disclosed. These anisotropic structures allow for an accurate implementation of phase, group delay, and group delay dispersion, while simultaneously making it possible to realize a polarizationinsensitive, diffraction-limited and achromatic metalens for wavelength, e.g., ?=from about 460 nm to about 700 nm. The approach of polarization-insensitivity can be also applied for other metasurface devices with applications in, e.g., imaging and virtual or augmented reality.

Abstract: An optical component comprises a metasurface comprising nanoscale elements. The metasurface is configured to receive incident light and to generate optical outputs. The geometries and/or orientations of the nanoscale elements provide a first optical output upon receiving a polarized incident light with a first polarization, and provide a second optical output upon receiving a polarized incident light with a second polarization that is different from the first polarization.

Abstract: Metasurface optical components deposited on the surface of a substrate are used to alter incident light. The metasurface optical components comprise a pattern of silicon dielectric resonators that have nonperiodic gap distances between adjacent silicon dielectric resonators; and each silicon dielectric resonator is an elongated rectangular prism that has a width, a length, and a thickness. Incident light is directed to the metasurface optical components, wherein the gap distances, the widths, and the thicknesses are configured to scatter the incident light and impart a phase shift, ranging at least from 0 to 2?, on an outgoing light. Each dielectric resonator has a rectangular cross-section in a plane perpendicular to the substrate surface such that a first phase shift is imparted for a transverse-electric (TE) component of the incident light and a second phase shift is imparted for a transverse-magnetic (TM) component of the incident light.

Abstract: An optical system, comprising: (i) multiple input optical fibers; (ii) an optical mode multiplexer/demultiplexer coupled to said input optical fibers with, said optical mode multiplexer/demultiplexer comprising a plurality of metamaterial structures having length and forming at least one stage of metamaterials, the at least one stage of metamaterials is being situated on a surface of the optical mode multiplexer/demultiplexer facing the input optical fibers, and the at least one stage of metamaterials is oriented at angles between 60 and 120 degrees relative to the axis of the input fibers; and the metasurfaces are structured to receive a first optical signal having a first mode from at least one of said multiple input optical fibers and convert the first mode to a different mode.

Abstract: An optical component comprises a metasurface comprising nanoscale elements. The metasurface is configured to receive incident light and to generate optical outputs. The geometries and/or orientations of the nanoscale elements provide a first optical output upon receiving a polarized incident light with a first polarization, and provide a second optical output upon receiving a polarized incident light with a second polarization that is different from the first polarization.

Abstract: A system can include a wavefront-shaping device. The wavefront-shaping device can project one or more light sheets along an optical path. The one or more light sheets can include one or more light threads. Each of the one or more light threads can be non-diffracting and structured along the optical path. At least one plane of the one or more light sheets can be non-parallel to a plane of the wavefront-shaping device.

Abstract: An optical component includes a substrate and a metasurface comprising one or more linearly birefringent elements. The linearly birefringent elements define a grating configured to implement parallel polarization analysis for a plurality of polarization orders for incident light of an arbitrary polarization.