Abstract:
An apparatus has a waveguide that includes a multiferroic medium. A controller is configured to apply a mechanical strain or a control electric or magnetic field to the multiferroic medium. The multiferroic medium has a dielectric permittivity or magnetic permeability that is responsive to the strain or the control field.
Abstract:
An optical frequency converter that uses a nonlinear optical process to transfer energy between a surface-plasmon (SP) wave that is guided along an electrically conducting strip and a light beam that is guided along an optical waveguide whose core is adjacent to the electrically conducting strip. The optical frequency converter has a periodic structure that spatially modulates the nonlinear susceptibility of the waveguide core with a spatial period that is related to a momentum mismatch in the nonlinear optical process. The spatial modulation provides quasi-phase matching for the SP wave and the light beam and enables efficient energy transfer between them.
Abstract:
A fabrication method produces a mechanically patterned layer of group III-nitride. The method includes providing a crystalline substrate and forming a first layer of a first group III-nitride on a planar surface of the substrate. The first layer has a single polarity and also has a pattern of holes or trenches that expose a portion of the substrate. The method includes then, epitaxially growing a second layer of a second group III-nitride over the first layer and the exposed portion of substrate. The first and second group III-nitrides have different alloy compositions. The method also includes subjecting the second layer to an aqueous solution of base to mechanically pattern the second layer.
Abstract:
A polarization-diverse apparatus includes a polarization-sensitive negative-refractive-index (NRI) medium and a polarization splitter. The polarization splitter is configured to receive an electromagnetic input signal, to direct a first polarization component of the received input signal to a first path segment, and to direct a second polarization component of the received input signal to a separate second path segment. The medium has first and second signal ports. The first port is at an end of the first path segment. The second port is at an end of the second path segment. The medium outputs an altered signal from one of the ports in response to receiving the input signal at the other of the ports. In a preferred embodiment, the medium has an internal optical axis, and the polarizations of the first and second components are oriented relative to that axis so that effect of altering the input signal is enhanced. The two path segments may include polarization-maintaining waveguides.
Abstract:
An optical fiber transmission system includes a series of optical fiber transmission spans and one or more all-optical signal processors. The optical fiber transmission spans are connected to form an optical communication path. Each all-optical signal processor directly connects a corresponding adjacent pair of the spans. Each all-optical signal processor includes an optical wavelength converter having input and output ports and a dispersion adjustment module connected to the input port of the optical wavelength converter of the same processor. The dispersion module is also configured to adjust cumulative dispersions of some received optical pulses to be outside of a range for the cumulative dispersions of corresponding optical pulses in the span directly preceding the same processor.
Abstract:
Electro-optic elements are formed in metal oxide films, such as lithium niobate, on a substrate such as lithium niobate for utilization in electro-optical devices. The electro-optic elements include trenches in the lithium niobate selected to improve the performance of the device. Traveling wave modulators may be formed with a waveguide having first and second arms, electrodes over the lithium niobate layer, and trenches formed in the layer to focus the electric field in the waveguide, resulting in improved modulator performance.
Abstract:
An energy-management system for controlling energy consumption in a relatively small network of energy-consuming/generating objects connected to an electricity grid and located, e.g., at a user premises. The energy consumption is managed through a programmable gateway device that can be accessed remotely, e.g., through a smart-meter network of the utility company or through a short-range wireless link. A user interface for the remote access can be implemented, e.g., using a smart phone or a tablet. In operation, the gateway device advantageously provides the user and/or the utility company with numerous opportunities for realizing cost and/or energy savings through appropriate and timely response to various actionable conditions, such as price-of-electricity fluctuations, configuration-modification requests, failure notices, service requirements, hazard signals, etc.
Abstract:
A method of processing an electromagnetic signal, comprising includes configuring a waveguide that includes a multiferroic medium to propagate the electromagnetic signal. A mechanical strain or a control electrical or magnetic field is applied to the waveguide such that the applying changes a permittivity or a permeability of the medium. The electromagnetic signal is propagated through said waveguide while performing the applying.
Abstract:
A method of processing an electromagnetic signal, comprising includes configuring a waveguide that includes a multiferroic medium to propagate the electromagnetic signal. A mechanical strain or a control electrical or magnetic field is applied to the waveguide such that the applying changes a permittivity or a permeability of the medium. The electromagnetic signal is propagated through said waveguide while performing the applying.
Abstract:
System including electromagnetic radiation source and electromagnetic radiation detector. Electromagnetic radiation source is configured to excite, with electromagnetic radiation having first source frequency, object configured for suppressing responsive emission of electromagnetic radiation having first source frequency. Electromagnetic radiation detector is configured to receive responsive emission of electromagnetic radiation from object. System is configured to detect presence of object. Method includes exciting, with electromagnetic radiation having first source frequency, object configured for suppressing responsive emission of electromagnetic radiation having first source frequency. Method includes receiving responsive emission of electromagnetic radiation from object and utilizing responsive emission to detect presence of object.