Abstract: In one embodiment, a method of producing an optoelectronic nanostructure includes preparing a substrate; providing a quantum well layer on the substrate; etching a volume of the substrate to produce a photonic crystal. The quantum dots are produced at multiple intersections of the quantum well layer within the photonic crystal. Multiple quantum well layers may also be provided so as to form multiple vertically aligned quantum dots. In another embodiment, an optoelectronic nanostructure includes a photonic crystal having a plurality of voids and interconnecting veins; a plurality of quantum dots arranged between the plurality of voids, wherein an electrical connection is provided to one or more of the plurality of quantum dots through an associated interconnecting vein.

Abstract: The present invention is an efficient method for the fabrication of three-dimensional structures in GaAs-based materials. The method is particularly suitable for the realization of 3D photonic crystals. The method relies on the observation that the oxidation rate of Ga1-xA1xAs in water-vapor atmosphere is a strong function of the aluminum content in the alloy. Thus, a stack of Ga1-xA1xAs layers with varying concentration of A1 is grown on GaAs substrate. The top surface is patterned with an array of holes, which are then transferred to the underlying layers by dry etching. Subjecting the so-prepared structure to oxidation in water vapor atmosphere at an elevated temperature results in lateral oxidation of the material exposed by the etched holes. The lateral oxidation depth depends on aluminum content in a particular layer. The oxide is then removed by an aqueous solution of hydrofluoric acid and a three-dimensional array of voids ensues.

Abstract: A method for generating images in polymers comprising: preparing a template with an extruding desired pattern; contacting a surface of a polymer with a desired pattern of the extruded surface of the template; treating the surface of the polymer with at least one of a liquid acid and vapor; treating the surface of the polymer with a high temperature for crosslinking; separating the template and polymer and revealing an acid imprint of the desired pattern on the surface of the polymer; baking the polymer to drive diffusion of the acid; and developing the polymer with at least one of a wet and dry process to produce a negative pattern in the polymer.

Abstract: A terahertz (THz) frequency radiation source to emit radiation in a narrow wavelength band within a range of about 3 ?m to 3000 ?m. This source includes: a broad bandwidth emitter to generate a broad bandwidth emitted wavelength band within the wavelength range; a first planar waveguide optically coupled to the broad bandwidth emitter to transmit the broad bandwidth radiation; a disk resonator evanescently coupled to the first planar waveguide with a resonance wavelength band within the emitted wavelength band; and a second planar waveguide evanescently coupled to the disk resonator to transmit radiation in the narrow wavelength band. The emitted wavelength band has a bandwidth greater than or equal to about 0.01 times a mid-band wavelength. The resonance wavelength band has a resonance wavelength bandwidth of less than or equal to about 0.25 times the emitted bandwidth. The narrow wavelength band is substantially equal to the resonance wavelength band.

Abstract: A method for manufacturing optical components in a three-dimensional photonic crystal lattice. A first resist (9) is coated on a substrate (10) and exposed to an e-beam (11), to produce an imaged area (12). Another resist coating is applied to thicken the resist (13) and an interference exposure (15) is used to image the result. This is developed to form periodic voids (16), which may be filled with a materials having a high refractive index to form a pattern (18 and 12) when the resist (13) is removed.

Abstract: An optical device includes an antimonide-containing substrate, and an antimonide-containing n-doped layer provided on the substrate. The optical device further includes an antimonide-containing i-doped layer provided on the n-doped layer, an antimonide-containing p-doped layer provided on the i-doped layer, and an antimonide-containing p+-doped layer provided on the p-doped layer.

Abstract: A hardware-based acceleration platform for computational electromagnetic algorithms, specifically the finite-difference time-domain (“FDTD”) method, comprises reformulating the FDTD algorithm in order to make it more hardware friendly. This reformulation makes use of split fields at every node in the mesh, and combines total- and scattered-field formulations into a single, hybrid formulation. By precomputing coefficients for the nodes in the mesh, it is possible for a single set of equations to support plane waves, point sources, PML ABCs, and PEC walls. In the method sources are determined by means of a lookup table, rather than through direct hardware computations. All of these modifications enable the hardware designer to much more easily develop an FDTD accelerator.

Abstract: A fiber Bragg grating compression sensor and a flexure mount that is attached to the sensor to significantly enhance its compression sensitivity. By incorporating the flexure mount, compressive forces are converted to tensile forces allowing an entire new set of measurement possibilities. The sensor may be used in implantable tendon and ligament force sensing or as a generalized compression sensor.

Abstract: A process for making photonic crystal circuit and a photonic crystal circuit consisting of regularly-distributed holes in a high index dielectric material, and controllably-placed defects within this lattice, creating waveguides, cavities, etc. for photonic devices. The process is based upon the discovery that some positive ultraviolet (UV) photoresists are electron beam sensitive and behave like negative electron beam photoresists. This permits creation of photonic crystal circuits using a combination of electron beam and UV exposures. As a result, the process combines the best features of the two exposure methods: the high speed of UV exposure and the high resolution and control of the electron beam exposure. The process also eliminates the need for expensive photomasks.

Abstract: A computer hardware configuration for performing the pseudo-spectral time-domain (PSTD) method on data. The hardware configuration includes a forward fast Fourier transform (FFT) unit that calculates a forward fast Fourier transform (FFT) from the data, and a complex multiplication unit that receives the FFT-processed data and calculates a spatial derivative in the frequency domain from the FFT-processed data. The hardware configuration further includes an inverse fast Fourier transform (IFFT) unit that converts the spatial derivative in the frequency domain from the complex multiplication unit into the time domain, and a computation engine that solves a PSTD equation based upon the spatial derivative in the time domain received from the IFFT unit.

Abstract: Methods and apparatus for detecting waves are disclosed. The waves are detected by modulating an optical carrier signal having a carrier signal frequency component at a carrier frequency with wave signals at one or more detection frequencies, optically removing the carrier signal frequency component from the modulated optical carrier signal, and detecting an energy level of the modulated optical carrier signal after removal of the carrier signal frequency component, the energy level indicative of the presence of the wave signals.

Abstract: An electro-optical switch implemented in coupled photonic crystal waveguides is disclosed. The switch is proposed and analyzed using both a finite-difference time-domain (“FDTD”) method and a plane wave expansion (“PWM) method. The switch may be implemented in a square lattice of silicon posts in air, as well as in a hexagonal lattice of air holes in a silicon slab. Switching occurs due to a change in the conductance in the coupling region between the photonic crystal waveguides, which modulates the coupling coefficient and eventually causes switching. Conductance may be induced electrically by carrier injection or optically by electron-hole pair generation. The electro-optical switch has low insertion loss and optical crosstalk in both the cross and bar switching states.

Abstract: Disclosed herein is an organization of cache memory for hardware acceleration of the FDTD method. The organization of cache memory for hardware acceleration of the FDTD method provides a substantial speedup to the finite-difference time-domain (FDTD) algorithm when implemented in a piece of digital hardware. The organization of cache memory for hardware acceleration of the FDTD method utilizes a very high bandwidth dual-port on-chip memory in a particular way. By creating many small banks of internal memory and arranging them carefully, all data dependencies can be statically wired. This allows for a many-fold speedup over SRAM-based solutions and removes the burden of data dependence calculation that streaming SDRAM-based solutions must perform.

Abstract: A method for fabricating a flip-chip semiconductor device having plural conductive polymer bumps includes forming plural molds on a substrate using a photolithographic technique; filling the molds by applying and spinning a layer of conductive polymer material onto the substrate; polishing the conductive polymer material layer to remove excess conductive material from a surface of the substrate; and stripping the plural molds from the substrate to reveal the plural bumps. In various aspects of disclosure, either positive resist or negative resist may be used. The electrical contact resistance compares favorably with squeegee-based bumps; there is an improvement in the contact resistance of the bumps patterned using polishing techniques in comparison to that of squeegee-based conductive polymer bumps.