摘要:
Various embodiments of the present invention are directed to photonic switches and switch fabrics employing the photonic switches. In one embodiment of the present invention, a photonic switch comprises a first waveguide disposed on a surface of a substrate in proximity to an opening in the substrate, and a second waveguide crossing the first waveguide and positioned in proximity to the opening in the substrate. The photonic switch includes a tunable microring resonator disposed on the surface of the substrate adjacent to the first waveguide and the second waveguide and configured with an opening aligned with the opening in the substrate. The photonic switch also includes a wire having a first end and a second end and configured to pass through the opening in the microring and the opening in the substrate.
摘要:
An apparatus and related methods for modulating an electromagnetic radiation beam are described. A composite material is positioned in the path of the radiation beam, the composite material comprising a plurality of commonly oriented metallic first lines spaced apart by less than a wavelength of the radiation beam and a plurality of commonly oriented metallic second lines also spaced apart by less than that wavelength. The second lines are positioned in a crossing arrangement with the first lines, a crosspoint location being defined where each first line crosses each second line. An electrically programmable impedance memory element is positioned at each crosspoint location and is electrically coupled between the first and second lines corresponding to that crosspoint location, each impedance memory element having an electrically programmed state. The composite material modulates the radiation beam according to the electrically programmed states of the impedance memory elements.
摘要:
Dispersion compensation for an optical signal having a first frequency range is described. The optical signal is applied to a dispersion compensating material having a negatively refracting behavior within the first frequency range. The dispersion compensating material is tuned by application of a control signal that varies at least one characteristic of the dispersion compensating material associated with the negatively refracting behavior.
摘要:
An apparatus and related methods for spectroscopic analysis of analyte molecules is described. The analyte molecules are disposed near a metallic film that is positioned between a first medium on a first side and a second medium on a second side, the second medium being of higher refractive index than the first medium. A radiation source provides excitation radiation that propagates through the second medium toward the metallic film. The second medium and the metallic film are positioned in evanescent communication with respect to the excitation radiation, and the metallic film comprises lithographically patterned features designed to intensify surface plasmon resonance along the metallic film to promote the emission of Raman radiation from the analyte molecules. A radiation detector detects the Raman radiation emitted from the analyte molecules.
摘要:
An assembly for monitoring an environment includes a RFID tag and at least one sensor assembly. The sensor assembly is configured to sense information regarding the environment around the assembly and convert a sensed event into power to at least partially power operation of the RFID tag.
摘要:
A composite material with at least one of a negative effective permittivity and a negative effective permeability for incident radiation of at least one wavelength is described. The composite material comprises conductive structures that are substantially random with respect to at least one of size, shape, orientation, and location.
摘要:
A device for deflecting an incident radiation beam through a steering angle to produce a deflected radiation beam is described. The device comprises a photonic crystal receiving the incident radiation beam at a dynamically controlled incidence angle. The photonic crystal is configured to negatively refract the incident radiation beam such that relatively large controlled variations of the steering angle are provided by relatively small controlled variations of the incidence angle.
摘要:
Methods of forming NERS-active structures are disclosed that include ordered arrays of nanoparticles. Nanoparticles covered with an outer shell may be arranged in an ordered array on a substrate using Langmuir-Blodgett techniques. A portion of the outer shell may be removed, and the exposed nanoparticles may be used in a system to perform nanoenhanced Raman spectroscopy. An ordered array of nanoparticles may be used as a mask for forming islands of NERS-active material on a substrate. NERS-active structures and an NERS system that includes an NERS-active structure are also disclosed. Also disclosed are methods for performing NERS with NERS-active structures.
摘要:
An assembly for monitoring an environment includes a RFID tag and at least one sensor assembly. The sensor assembly is configured to sense information regarding the environment around the assembly and convert a sensed event into power to at least partially power operation of the RFID tag.
摘要:
Spin-polarized electrons can be efficiently extracted from an n-doped semiconductor layer (n-S) by forming a modified Schottky contact with a ferromagnetic material (FM) and a δ-doped layer at an interface under forward bias voltage conditions. Due to spin-selection property of the FM-S junction, spin-polarized carriers appear in the n-doped semiconductor layer near the FM-S interface. If a FM-n-n′-p heterostructure is formed, where the n′ region is a narrower gap semiconductor, polarized electrons from the n-S region and holes from the p-S region can diffuse into the n′-S region under the influence of independent voltages applied between the FM and n′ regions and the n′ and p regions. The polarized electrons and holes recombine in the n′-S region and produce polarized light. The polarization can be controlled and modulated by controlling the applied voltages.