Abstract: A read/write head for an optical storage medium is provided. The read/write head comprises a waveguide having an end face and a plasmon-enhanced device provided on the end face of the waveguide. The plasmon-enhanced device comprises a metal film having a first surface and a second surface, the first surface being fixed to the waveguide end face, the metal film having an aperture provided therethrough. The metal film has a periodic surface topography provided on at least one of the first and second surfaces of the metal film. Light incident on one of the surfaces of the metal film interacts with a surface plasmon mode on at least one of the surfaces of the metal film thereby enhancing transmission of light through the aperture in the metal film which is directed onto and/or collected from the optical storage medium. A read/write head with an integral light source is also provided.

Abstract: An apparatus for enhanced light transmission is provided. The apparatus comprises a metal film having a first surface and a second surface, at least one aperture being provided in the metal film and extending from the first surface to the second surface. The at least one aperture comprises an entrance portion disposed on the first surface of the metal film and an exit portion disposed in the second surface of the metal film, each portion having a cross-sectional area in the plane of the corresponding metal film surface, wherein the cross-sectional area of the entrance portion is not equal to the cross-sectional area of the exit portion. A periodic surface topography is provided on at least one of the first and second surfaces of the metal film, the periodic surface topography comprising a plurality of surface features, wherein the geometry of each aperture entrance portion substantially matches the geometry of the surface features.

Abstract: An apparatus for enhanced light transmission is provided. The apparatus comprises a metal film having a first surface and a second surface, at least one aperture being provided in the metal film and extending from the first surface to the second surface. The at least one aperture comprises an entrance portion disposed on the first surface of the metal film and an exit portion disposed in the second surface of the metal film, each portion having a cross-sectional area in the plane of the corresponding metal film surface, wherein the cross-sectional area of the entrance portion is not equal to the cross-sectional area of the exit portion. A periodic surface topography is provided on at least one of the first and second surfaces of the metal film, the periodic surface topography comprising a plurality of surface features, wherein the geometry of each aperture entrance portion substantially matches the geometry of the surface features.

Abstract: A semiconductor laser with a rewritable wavelength stabilizer which comprises a laser mirror made of a grating written into a photorefractive material, in which the oscillation wavelength of the laser diode is determined by the period of the grating. This allows the refractive index of the grating to be changed by illuminating the photorefractive material after cooling thereof to a temperature at which most of the doped impurities form DX centers. The grating can be erased by heating the photorefractive material to a temperature at which most DX centers are ionized, which erases the grating. Thereafter the photorefractive material is cooled again to a temperature at which most impurities become DX centers, and a new grating can be written in the photorefractive material. The wavelength of the semiconductor laser can be changed repeatedly by erasing and rewriting the grating therein.

Abstract: A holographic data storage and/or retrieval apparatus having a spherical holographic recording medium and addressing means for rotating the recording medium to selectively expose the recording medium to data and reference beams at predetermined rotational positions. Whereby image data contained in the data beam is recorded in the recording medium and/or a data beam containing image data is reconstructed from the recording medium.

Abstract: A method for dynamically refreshing a holographic data storage medium wherein data is stored in a plurality of data pages, each of which comprises a two dimensional pattern of pixel data. Each data page is stored by interfacing an image or a Fourier transform of the data page with a reference beam to form a holographic recording of the data page in the holographic medium. Pursuant to the method, all of the data pages are classified as either good pages, each of which was written into storage less than a threshold time ago related to the decay of the holographic recording, or empty pages available for writing, or self-erasing pages which are self-erasing with time. At sequential time intervals, the oldest good page is read which then becomes a self-erasing page, and its data is rewritten into an empty page which then becomes the youngest good page, and the oldest self-erasing page becomes an empty page.

Abstract: A compound semiconductor that is suitably doped to exhibit the DX effect is irradiated with an optical beam of spatially varying intensity whereby localized regions of persistently higher conductivity and lower refractive index are created in the semiconductor where sufficient intensity of the beam was incident. The persistently higher conductive region can be used to bridge selected gaps in conductive paths on a support member use in memory device and the regions of lower refractive index can be used to providing guiding in a wave guide, to form high resolution gratings, or to form holograms.

Abstract: A point-to-point optical network for interconnecting processing elements uses a two-dimensional array of chips, each of which includes a two-dimensional array of lasers that are used to target a two-dimensional array of photodetectors. A two-dimensional array of lenslets together with a spherical lens are used to focus light from a laser in the j, k position in any one of the laser arrays in any one of the chips on the particular photodetector in the j,k position in the photodetector array.

Abstract: A mesh-connected tree (MCT) interconnect topology network which is a two-dimensional interconnect topology combining aspects of a conventional tree-network and a two-dimensional nearest-neighbor mesh network is implemented as a planar optical interconnect network.

Abstract: An information processing system uses a planar optical waveguide as a shared medium for a plurality of its subsystems. To this end, each subsystem is provided with a light emitting diode to broadcast information pulses into the shared medium and a photodetector for receiving the information pulses broadcast by the light emitting diodes. This thereby reduces the need for conductive interconnections between subsystems. Additionally, a number of planar optical waveguides can be stacked on a support and different compositions of subsystems communicate with one another by using different waveguides of the stack. The system can be adapted for time-division, space-division and frequency division multiplexing.

Abstract: Full duplex operation is achieved in a lightwave communication system by employing terminals having a distributed Bragg reflector (DBR) laser having separate electrically controllable Bragg reflector and gain sections. While operating as the basic heterodyne reception element, the DBR laser simultaneously generates lightwave signals for transmission to other terminals. External circuits process the electrical (intermediate frequency) signals from the simultaneously modulated and signal mixing laser to extract received information. In one embodiment, full duplex operation is described for an FSK lightwave communication system.

Abstract: The present invention relates to millimeter waveguide shorts and methods for making said shorts wherein an exemplary rectangular cross-sectioned waveguide short comprises a base substrate such as steel shimstock or foil having a width equal to the associated millimeter waveguide, a raised portion disposed laterally on both sides of the substrate at alternate quarter-wavelength sections adjacent one end of the substrate. The raised portions comprise a first layer of good electrically conductive material disposed on the substrate and a second layer of an insulating material formed atop the first layer. Alternatively, the exposed substrate sections can be gold plated. A preferred method comprises the steps of masking alternate quarter-wavelength sections of the exposed major surfaces adjacent one end of the substrate, depositing the first layer material on the unmasked quarter-wavelength sections and depositing the second layer material on the exposed major surfaces of the first layer material.