Abstract: An oxidative methane coupling (OCM) reactor has a reactor vessel that defines a reactor vessel interior. The reactor vessel having opposite ends and a central longitudinal axis that extends between the opposite ends. A catalyst bed assembly is positioned within the reactor vessel interior having a catalyst bed containing a layer of OCM catalyst of a uniform thickness. The catalyst bed assembly divides the reactor vessel interior into an upstream zone and a downstream zone. The catalyst bed has an upstream face for receiving the one or more flowing feed gases of methane and oxygen gas as a flowing mixture from the upstream zone. The upstream face of the catalyst bed is configured to have a total area that exceeds the largest transverse cross-sectional area of the interior of the reactor vessel that is perpendicular to the central longitudinal axis of the reactor vessel.

Abstract: Wide-angle optical functionality is beneficial for imaging and image projection devices. Conventionally, wide-angle operation is attained by a complicated assembly of optical elements. Recent advances have led to meta-surface lenses or meta-lenses, which are ultra-thin planar lenses with nanoantennas that control the phase, amplitude, and/or polarization of light. Here, we present a meta-lens capable of diffraction-limited focusing and imaging over an unprecedented >170° angular field of view (FOV). The lens is integrated on a one-piece flat substrate and includes an aperture on one side and a single meta-surface on the other side. The meta-surface corrects third-order Seidel aberrations, including coma, astigmatism, and field curvature. The meta-lens has a planar focal plane, which enables considerably simplified system architectures for imaging and projection.

Abstract: Disclosed are methods and systems for desulfurization of CO-rich streams. A method can include contacting a CO-rich gas stream with activated carbon and/or contacting the CO-rich gas stream with a zinc-oxide sorbent material at a temperature of ( ) to 50° C. to remove at least a portion of the sulfur-containing compounds present in the stream.

Abstract: Reversible phase-change materials (PCMs) can be added to or incorporated into meta-lenses, wave plates, waveguides, gratings, and other optical components to form active optical devices with controllable and adjustable optical characteristics. Local heating can be used to induce solid-state phase changes and large refractive index changes in the PCMs. The phase and index changes can provide large changes in the device's optical characteristics. Optical devices with PCM can be used for imaging applications, orbital angular momentum control, photonic integrated circuits and optical communication systems, beam steering, and other application.

Abstract: Meta-optic systems are described that include multi-function metasurfaces formed from a plurality of meta-atoms. A multi-function metasurface can exhibit two or more different optical functions for two or more different states of light incident on the metasurface. Different states of light include different polarizations, different wavelengths, and different angles of incidence. Different optical functions include distance sensing, converging, diverging, image formation, and patterned light formation. The multi-function metasurface can selectively impart different phase profiles to an incident beam depending on the incident beam's state of light.

Abstract: An optical pattern projection device includes a light emitter or light emitter array and one or more flat optics layers configured to project and split light beams from the light emitters to generate a projected light pattern including multiple sub-patterns each corresponding to one of the light emitters. The flat optics layers may include a single optical metasurface containing superposed beam shaping and/or projection phase profile and a beam splitting phase profile. Alternatively, the flat optics layers may include two optical metasurfaces each containing a light shaping and/or projection phase profile, which together produce a linear relationship between light emitter position and corresponding beam projection angle, and one or both of the metasurfaces further contains a superposed beam splitting phase profile. The light shaping and/or projection phase profile may have a function similar to a micro-lens array. A structured light camera combining optical pattern projection and detection is also provided.

Abstract: System for free-space light coupling between 2-dimensional light transmitter and receiver arrays using flat optics. The system includes: a transmitter array configured to emit one or more light beams; a first flat optic configured to receive the light beams from the transmitter array and generate one or more intermediate light beams; a first spacer disposed between the light transmitter array and the first flat optic; a receiver array; a second flat optic configured to receive the intermediate light beams and generate one or more output light beams toward the receiver array; and a second spacer disposed between the second flat optic and the light receiver array. The TX and RX portions of the light coupling system may be used in LiDAR systems as the light emitter (beam steerer) and detector, respectively. The flat optics are configured to provide a wide field of view for the LiDAR.

Abstract: A wide field-of-view sensor or projector includes a transparent substrate with one or more apertures on one side, and one or more chip stacks joined to the opposite side. Each chip stack includes a flat optics layer (e.g., metasurface), at least one spacer layer, an optional filter layer, and either an image sensor or a light source. In one example, two apertures and two corresponding chip stacks are provided; both chip stacks include image sensors but different metasurfaces and filters to capture different information from the scene. In an alternative embodiment, the two chip stacks include a light source and an image sensor, to function as a light projector and a light receiver, respectively. In other examples, two apertures and a single chip stack are provided, where the single chip stack include two metasurface and/or two filters corresponding to the two apertures.

Abstract: Meta-lens based ocular imaging, near-eye display, and eye-tracking systems are described. The systems can include a single focusing optic and an integrated circuit that provides illumination light and includes an imaging array. The focusing optic includes meta-atoms formed on a substrate. The systems may have no moving parts and achieve imaging or image-projection fields-of-view approaching or exceeding 180 degrees. Because of their low part count, the systems can be robust and have a very small form factor.

Abstract: Meta-lens based ocular imaging, near-eye display, and eye-tracking systems are described. The systems can include a single focusing optic and an integrated circuit that provides illumination light and includes an imaging array. The focusing optic includes meta-atoms formed on a substrate. The systems may have no moving parts and achieve imaging or image-projection fields-of-view approaching or exceeding 180 degrees. Because of their low part count, the systems can be robust and have a very small form factor.

Abstract: The present technology is related to optics and optical systems, particularly to photonic packaging, optical coupling, optical interconnects, micro-optics, and their fabrication. The present technology includes free-form micro-optical coupler architectures and systems with superb optical performance and a high-throughput method of fabricating large-area coupler arrays for scalable manufacturing. Embodiments include chip-to-fiber-array, chip-to-chip, chip-to-interposer, and chip-to-free-space couplers for applications including photonic packaging, optical communications, LiDAR, optical trapping and manipulation, augmented reality, virtual reality, and sensing.

Abstract: An ethylene oxide (EO) production process comprising (a) introducing a first reactant mixture (C2H6, O2) to a first reactor to produce a first effluent stream (C2H4, C2H6, O2); (b) introducing a second reactant mixture to a second reactor to produce a second effluent stream (EO, C2H4, C2H6, O2); wherein the second reactant mixture comprises at least a portion of first effluent stream; (c) separating the second effluent stream into an EO product stream (EO) and recycle stream (C2H4, C2H6, O2); wherein ethylene is not separated from recycle stream and/or first effluent stream; and (d) recycling a first portion of recycle stream to the first reactor, and a second portion of recycle stream to the second reactor; wherein recycle split ratio <0.6; and wherein recycle split ratio is defined as ratio of volumetric flowrate of first portion of recycle stream divided by the sum of volumetric flowrates of first portion and second portion of recycle stream.

Abstract: A sensor, such as a photoplethysmography sensor, for non-invasively monitoring a characteristic of an organism, such as a vital body sign. The sensor has multiple light sources disposed on a substrate and an array of optical probing channels for conveying light from the light sources to a probed region. Each detector pixel of an array of detector pixels receives light from a respective optical detection channel after interaction with a subregion of the probed region and spatial filtering, and generates a corresponding pixel signal.

Abstract: Disclosed herein are systems and processes for the conversion of a methane feedstock to C2+ hydrocarbons.

Abstract: An optical device as described herein includes a host substrate fabricated from a dielectric material transparent in the Infrared range. Additionally, the optical device as discussed herein includes multiple elements disposed on the host substrate. The multiple elements are spaced apart from each other on the host substrate in accordance with a desired pattern. Each of the multiple elements disposed in the host substrate is fabricated from a second material having a refractive index of greater than 4.5. Such an optical device provides an improvement over conventional optical devices that operate in the Infrared range.

Abstract: An ethylene oxide (EO) production process comprising (a) introducing a first reactant mixture (C2H6, C2H4, O2) to a first reactor to produce a first effluent stream (C2H4, C2H6, O2), wherein the mole fraction of ethylene in first effluent stream is greater than in first reactant mixture; wherein the first reactant mixture is characterized by a molar ratio of ethylene to ethane of ?1.3; (b) introducing the first effluent stream to a second reactor to produce a second effluent stream (EO, C2H4, C2H6, O2); (c) separating the second effluent stream into an EO product stream (EO) and recycle stream (C2H4, C2H6, O2); wherein ethylene is not separated from recycle stream and/or first effluent stream; and (d) recycling at least a portion of recycle stream to the first reactor, and a portion of recycle stream to the second reactor.

Abstract: An ethylene oxide (EO) production process comprising (a) introducing a first reactant mixture (C2H6, C2H4, O2) to a first reactor system to produce a first effluent stream (C2H4, C2H6, O2), wherein the mole fraction of ethylene in first effluent stream is greater than in first reactant mixture; wherein the first reactor system is characterized by a first reactor system operating temperature of 270° C.-320° C.; wherein the first reactor system comprises oxidative dehydrogenation (ODH) stage(s); (b) introducing the first effluent stream to a second reactor to produce a second effluent stream (EO, C2H4, C2H6, O2); (c) separating the second effluent stream into an EO product stream (EO) and recycle stream (C2H4, C2H6, O2); wherein ethylene is not separated from recycle stream and/or first effluent stream; (d) recycling at least a portion of recycle stream to the first reactor system, and a optionally portion of recycle stream to the second reactor.

Abstract: An optical coherence tomography (OCT) engine includes a digital Fourier-Transform (dFT) spectrometer, a tunable delay line, and a high-speed optical phased array (OPA) scanner integrated onto a single chip. The broadband dFT spectrometer offers superior signal-to-noise ratio (SNR) and fine axial resolution; the tunable delay line ensures large imaging depth by circumventing sensitivity roll-off; and the OPA can scan the beams at GHz rates without moving parts. Unlike conventional spectrometers, the dFT spectrometer employs an optical switch network to retrieve spectral information in an exponentially scaling fashion—its performance doubles with every new optical switch added to the network. Moreover, it also benefits from the Fellgett's advantage, which provide a significant SNR edge over conventional spectrometers. The tunable delay line balances the path length difference between the reference and sample arms, avoiding any need to sample high-frequency spectral fringes.

Abstract: The present technology is related to optics, optical systems, and optically induced micro-/nano-fabrication methods. It includes metasurface optics, direct laser writing, and microscopy. Flat optic devices, architectures, and methods can achieve superb optical performance and structural simplicity compared to traditional bulk optical systems.

Abstract: Reflecting light beams off of microscale three-dimensional (3D) freeform surfaces can yield highly efficient coupling into and out of optical waveguides, optical fibers, and photonic chips. The structure of the 3D freeform reflective surface determines the shape of the reflected beam. This allows freeform reflectors to control the mode profile, rotation angle, and divergence angle of light beams. Control of beam shape enables mode matching between source output mode and target input mode, which results in low-loss optical coupling. An inventive freeform reflective surface can direct light beams in plane or out of plane via specular reflection or total internal reflection. A photonic integrated circuit with this type of freeform optical coupler can operate with a bandwidth range of at least 400 nm, potentially encompassing all visible or telecommunications wavelengths, and can be volume manufactured in photonic chips.