Abstract: A computer-implemented method is provided for designing a metalens. The metalens has a metasurface including nano-structures arranged on a substrate based on preliminary simulation data. The method includes partitioning the nano-structures into overlapping d-unit supercells such that every non-perimeter nano-structure is at the center of one d-unit supercell, computing a differentiable mapping function of the d-unit supercells that predicts the near-field over the unit cell at the center of the supercell from the design parameters of all the nanostructures in the supercell, jointly tuning the design parameters of all unit cells in the metalens to better approximate a target near field distribution over the entire metalens, by using a Jacobian of partial derivatives provided by the mapping function to solve for a locally optimal correction of all design parameters, and generating a fabricable design of the metalens based on the optimized parameters.

Abstract: A reconfigurable device is provided for splitting optical beams. The device includes an input port configured to receive an input beam including at least two primary wavelengths, a tunable splitter configured to separate the input beam into at least two beams via at least two routes corresponding to the at least two primary wavelengths, wherein each of the at least two routes is configured to propagate one of the at least two primary wavelengths of the input beam, wherein the tunable splitter includes a bottom electrode, a substrate on the bottom electrode, core segments arranged on the substrate, a top layer, support segments to connect the substrate and the top layer, a top electrode on the top layer, a controllable refractive index layer arranged to fill gaps between the substrate, the support segments, and the top layer; and at least two output ports configured to transmit the at least two beams propagated via the at least two routes.

Abstract: A computer-implemented artificial intelligence (AI) method is provided for a programmable photonic computer. The AI method includes processing input data, weight parameters, and conditional variables, and embedding the input data, weight parameters, and conditional variables into the programmable photonic computer by controlling a set of adjustable parameters. Light is injected into a set of input ports of the programmable photonic computer, where it is transformed through a series of interferometers and waveguides configured by the adjustable parameters. The transformed light is then detected at the output ports of the programmable photonic computer, and the detected light is output as an inference prediction for an AI task. This process represents a neural network transformation of the input data adjusted by the weight parameters.

Abstract: A method for producing a nitrile rubber, includes recovering a nitrile rubber from a latex of nitrile rubber by continuously feeding the latex of nitrile rubber and a coagulant into an extruder including a screw disposed inside a barrel to be rotatably driven, wherein the latex of nitrile rubber fed into the extruder contains 0.1 to 3 parts by weight of a hindered phenol-based antiaging agent having a molecular weight of 300 to 3000 relative to 100 parts by weight of the nitrile rubber.

Abstract: A photonic device for splitting optical beams includes an input port configured to receive an input beam having an input power, a power splitter including perturbation segments arranged in a first region and a second region of a guide material having a first refractive index, each segment having a second refractive index, wherein the first region is configured to split the input beam into a first beam and a second beam, wherein and the second region is configured to separately guide the first and second beams, wherein the first refractive index is greater than the second refractive index, and output ports including first and second output ports connected the power splitter to respectively receive and transmit the first and second beams.

Abstract: A reconfigurable optical processor is provided for processing optical signals. The device includes at least two input ports configured to receive input signals including at least one primary wavelength, a nanophotonic structure configured to separate the input beams into at least two beams, wherein the reconfigurable optical processor includes a lower electrode at the bottom, a substrate on the lower electrode, a cladding layer on the substrate, a nanophotonic structure waveguide layer, support materials to hold the insulating layer and the substrate, an upper electrode on the insulating layer, a variable refractive index layer arranged to fill gaps between the substrate, the nanophotonic structure, and the insulating layer; and at least two output ports configured to transmit at least two beams propagated.

Abstract: A method for a target image reconstruction is provided. The method includes emitting stepped frequency waveforms having different constant frequencies at different periods of time, modulating the stepped frequency waveforms into frequency ranges each having a first frequency and a second frequency, wherein each of the stepped frequency waveforms are increased from the first frequency to the second frequency based on a range function, wherein the modulated stepped frequency waveforms are arranged with some sparsity factor.

Abstract: A light emission device includes: a laser light source; an electric storage element for supplying a drive current to the laser light source; a plurality of switch elements connected in series to the laser light source; and an electrical element placed at least between a ground and an input part, for a switch opening/closing signal, of the switch element to which another one of the switch elements is connected on a downstream side, and configured to guide noise having a high level exceeding a voltage level of the switch opening/closing signal, to the ground.

Abstract: A printed wiring board includes a resin insulating layer, via conductors formed in the resin insulating layer, metal posts formed on the via conductors, respectively, and a solder resist layer formed on the resin insulating layer such that the metal posts have lower portions embedded in the solder resist layer and upper portions exposed from the solder resist layer, respectively. The metal posts are formed such that each of the metal posts has a top portion having a diameter in a range of 0.8 to 0.9 times a diameter of a respective one of the lower portions of the metal posts.

Abstract: A reconfigurable device is provided for splitting optical beams. The device includes an input port configured to receive an input beam including at least two primary wavelengths, a tunable splitter configured to separate the input beam into at least two beams via at least two routes corresponding to the at least two primary wavelengths, wherein each of the at least two routes is configured to propagate one of the at least two primary wavelengths of the input beam, wherein the tunable splitter includes a bottom electrode, a substrate on the bottom electrode, core segments arranged on the substrate, a top layer, support segments to connect the substrate and the top layer, a top electrode on the top layer, a controllable refractive index layer arranged to fill gaps between the substrate, the support segments, and the top layer; and at least two output ports configured to transmit the at least two beams propagated via the at least two routes.

Abstract: A computer-implemented method is provided for designing a metalens. The metalens has a metasurface including nano-structures arranged on a substrate based on preliminary simulation data.

Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.

Abstract: A method for producing a nitrile rubber, includes recovering a nitrile rubber from a latex of nitrile rubber by continuously feeding the latex of nitrile rubber and a coagulant into an extruder including a screw disposed inside a barrel to be rotatably driven, wherein the latex of nitrile rubber fed into the extruder contains 0.1 to 3 parts by weight of a hindered phenol-based antiaging agent having a molecular weight of 300 to 3000 relative to 100 parts by weight of the nitrile rubber.

Abstract: A photonic device for splitting optical beams includes an input port configured to receive an input beam having an input power, a power splitter including perturbation segments arranged in a first region and a second region of a guide material having a first refractive index, each segment having a second refractive index, wherein the first region is configured to split the input beam into a first beam and a second beam, wherein and the second region is configured to separately guide the first and second beams, wherein the first refractive index is greater than the second refractive index, and output ports including first and second output ports connected the power splitter to respectively receive and transmit the first and second beams.

Abstract: A system is provided for training a device design network. The system includes an interface configured to input data of a device, a memory to store the device design network including an encoder, a decoder, and an adversarial block, and a processor. The processor is, in connection with the memory, configured to update the encoder and the decoder based on a first loss function to reduce the difference between the input data and output data of the decoder, wherein the encoder is constructed by at least one convolutional layer followed by at least one parallel fully connected layer to extract features of a layout of the device, and update the adversarial block to construct by maximizing a second loss function.

Abstract: A method for a target image reconstruction is provided. The method includes emitting stepped frequency waveforms having different constant frequencies at different periods of time, modulating the stepped frequency waveforms into frequency ranges each having a first frequency and a second frequency, wherein each of the stepped frequency waveforms are increased from the first frequency to the second frequency based on a range function, wherein the modulated stepped frequency waveforms are arranged with some sparsity factor.

Abstract: A rolling bearing includes: an inner ring; an outer ring; a plurality of rolling elements provided between an inner ring raceway and an outer ring raceway; and a cage that holds the rolling elements at intervals in a circumferential direction. The cage includes an annular portion provided in a first axial direction with respect to the rolling elements, and a plurality of cage bars provided to extend in a second axial direction from the annular portion. The annular portion includes a contact surface that makes sliding contact with a shoulder portion. The cage bars each include a first projecting portion and a second projecting portion. The second projecting portion covers a part of the inner ring raceway on a side of the shoulder portion.

Abstract: A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch ?, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.

Abstract: A rolling bearing includes an inner ring, an outer ring, a plurality of balls, and a cage that holds the balls. The cage includes an annular portion and a plurality of cage bars. Each of the balls is received a pocket between each pair of cage bars that is adjacent in the circumferential direction. A portion of the pocket in a second axial direction opens with a dimension that is smaller than a diameter of the balls. The cage bar includes a flat surface that is continuous with an inner peripheral surface of the annular portion, and an inclined surface that extends away from the inner ring toward the second axial direction from the flat surface.

Abstract: An integrated grating coupler system includes a first chip having a first substrate, a first grating structure formed by first grating curves arranged on the first substrate and a cladding layer formed to cover the first grating structure, wherein the first chip include a first waveguide configured to receive a light beam from a first end via the first waveguide and transmit the light beam through a second end, a second chip having a second substrate and a second grating structure formed by second grating curves arranged on the second substrate, wherein the second chip is configured to receive the light beam from the second end of the first chip and transmit the light beam from an end of the second chip, and a common block configured to mount the first chip and second chip via a first submount and a second submount respectively, wherein the first and second submounts are arranged such that the light beam from the second end of the first chip is received at a top of the second chip.