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 provided in the metal film and extending from the first surface to the second surface, and a periodic surface topography provided on at least one of the first and second surface 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 at least one aperture in the metal film. The apparatus may have a single aperture or a plurality of periodically arranged apertures. Wavelength-selective optical filters, spatial optical filters, light collectors, near-field scanning optical microscope probes and photolithographic masks are also provided.

Abstract: Digital watermarking of audio, image, video or multimedia data is achieved by inserting the watermark into the perceptually significant components of a decomposition of the data in a manner so as to be visually imperceptible. In a preferred method, a frequency spectral image of the data, preferably a Fourier transform of the data, is obtained. A watermark is inserted into perceptually significant components of the frequency spectral image. The resultant watermarked spectral image is subjected to an inverse transform to produce watermarked data. The watermark is extracted from watermarked data by first comparing the watermarked data with the original data to obtain an extracted watermark. Then, the original watermark, original data and the extracted watermark are compared to generate a watermark which is analyzed for authenticity of the watermark.

Abstract: Thin, horizontal-plane Hall sensors for read-head in magnetic recordings and methods for fabricating the sensor provide a novel sensor exhibiting high sensitivity and high spatial resolution.

Abstract: The present invention is directed, inter alia, to a switch comprising: (A) a superconducting material whose field cooled and zero field cooled ac permittivities differ from each other, and whose field cooled and zero field cooled ac susceptibilities differ from each other, in a range of temperature below the superconducting transition temperature of the material; (B) means for applying a static magnetic field to said material; (C) means for controllably applying to said material an oscillating magnetic field of a magnitude effective to convert said material from a state exhibiting filed cooled permittivity to a state exhibiting zero field cooled permittivity; and (D) means for applying to said material a heat pulse effective to convert said material from a state exhibiting zero field cooled permittivity to a state exhibiting field cooled permittivity, said switch operating between a superconducting zero field cooled state and a superconducting field cooled state.

Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n.times.n blocks, such as the 8.times.8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8.times.8 blocks to form a set of N summed 8.times.8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain.

Abstract: A method for patterning materials according to a predetermined, three-dimensional pattern, as well as patterned materials produced by said methods, are provided. A template is prepared comprising a template material, the template having a plurality of pores therein, the plurality of pores comprising a negative of the predetermined, three-dimensional pattern. Colloidal nanocrystals sufficient to fill the pores in the template are also prepared. The pores in the template are filled with the colloidal nanocrystals. A quantum-dot solid is formed from the colloidal nanocrystals within the pores in the template, such that the colloidal nanocrystals are concentrated as close-packed nanocrystals within the pores in the template in the predetermined, three-dimensional pattern. If desired, a conventional solid may be obtained by sintering the close-packed nanocrystals within the pores of the template.

Abstract: In DNA computing there are DNA sequences which will substantially eliminate binding errors for molecules used in the computing processing. The elimination of binding errors will prevent extraction errors and binding during computations. A set of DNA sequences {Z.sub.j } and spacer sequence S.sub.0 must meet the criteria that there is no subsequence .chi. of length k, which occurs in any two sequences {Z.sub.j } or subsequence .chi. occurs in a sequence S.sub.0 Z.sub.j S.sub.0 and the complement .chi. occurs in a sequence S.sub.0 Z.sub.j S.sub.0, where Z.sub.j is at least of length k, so that it may be extracted.

Abstract: Thin, horizontal-plane Hall sensors for read-head in magnetic recordings and methods for fabricating the sensor provide a novel sensor exhibiting high sensitivity and high spatial resolution.

Abstract: A modular, high-intensity fiber optic color backlight for color displays wherein light is distributed to the display through side-emitting optical fibers. The optical fibers are ordered into an array of channels, wherein each channel contains a number of optical fibers. Each of the individual channels are separated by reflective channel isolators and each channel preferably carries light of a single color. Light detecting fibers are optionally installed in the module so that intensity data may be collected. Each module includes a mechanical and electrical interconnect so that individual modules may be combined, thereby producing displays of arbitrary size.

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 number-theoretic based algorithm provides for secure receipt-free voting. A vote generating center generates a choice of votes for each voter or vote chooser. The votes are encrypted, shuffled, and conveyed to a vote chooser along with information regarding how the votes were shuffled without being intercepted en route. The information is preferably sent along untappable secure channels. The method can incorporate validation of generation and shuffling of the votes using chameleon commitment and interactive proofs. The invention can be realized by current-generation personal computers with untappable channels and access to an electronic bulletin board.

Abstract: Segmentation of an image into separate regions is useful in many computer vision problems. The separate regions may be represented by their enclosing contours. A planar graph is constructed for each image. The optimal contour is determined by the assignment of edge costs and face weights of the graph. An algorithm is provided such that given a planar graph G = (V,E) where V is a set of nodes, E is a set of edges and each edge e is provided with a non-negative cost c(e) and each face f of the planar graph is provided with a non-negative weight w(f), and given a single node v in G and single face F adjacent to v which is viewed as the exterior face, then find a directed path P in G that starts and finishes at v and minimizes ##EQU1## where cost(P) is defined as the length of the path under c, and weight (P) is the weight of the faces that are separated from F by P. The contour that minimizes .zeta. is the optimal contour.

Abstract: A watermark is embedded into video/image/multimedia data using spread spectrum methodology. The watermark is extracted from watermarked data without the use of an original or unwatermarked version of the data by using MPEG/JPEG coefficients. The image to be watermarked is divided into subimages. Each subimage is embedded with a watermark. When extracting the watermark, the result from each subimage is combined to determine the originally embedded watermark.

Abstract: A unidirectional and bidirectional optical fiber couplers using polymer optical fibers having mirrors formed within the polymer optical fibers for reflecting optical signals. The mirrors comprise a notch having at least one surface angled with respect to the central axis of the optical fiber for reflecting the optical signal perpendicular to its central axis. A unidirectional embodiment allows input optical signals to be coupled from any combination of input optical fibers and transmitted into any combination of output optical fibers. A bidirectional embodiment allows optical signals from tapping fibers to be reflected in opposite directions along a first, or BUS optical fiber. Another aspect of the present invention is an apparatus and method for controlling the depth of the notch by monitoring residue power through the optical fibers while the notch is being cut.

Abstract: A metallic film has apertures located therein in an array arranged in a pattern so that when light is incident on the apertures, surface plasmons on the metallic film are perturbed resulting in an enhanced transmission of the light emitted from individual apertures in the array. The aperture array is used: to filter light of predetermined wavelength traversing the apertures, to collect light over a distance after traversing the apertures, to improve operation of near-field scanning optical microscopes, and to enhance light transmission through masks useable in photolithography.

Abstract: A method for solving the stereo correspondence problem transforms the problem into a maximum-flow problem. Once solved, the minimum-cut associated to the maximum-flow results in a disparity surface for the entire image at once. This global approach to stereo analysis provides a more accurate and coherent depth map than the traditional line-by-line stereo method. Moreover, the optimality of the depth surface is guaranteed and can be shown to be a generalization of the dynamic programming approach that is widely used in standard stereo. Results show improved depth estimation as well as better handling of depth discontinuities. While the worst case running time is O(n.sup.3 d.sup.3), the observed average running time is O(n d.sup.1.4) for an image size of n pixels and depth resolution d.

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: Generally speaking, in accordance with the invention, an optical transmission modulation apparatus is provided for modulating light transmitted through the apparatus. The apparatus comprises a metal film having a periodic array of subwavelength-diameter holes provided therein, and a supporting layer. At least a portion of the supporting layer has a selectively variable refractive index, the selectively variable refractive index portion being substantially adjacent to the metal film such that the metal film and the supporting layer form a perforated metal film unit. Selective variation of the refractive index of the selectively variable refractive index portion modulates the intensity of the light transmitted through the perforated metal film unit without substantially changing the direction of the light. Flat panel displays, spatial light modulators and tunable optical filters based on the optical transmission control apparatus are also provided.

Abstract: A hybrid neural network system for object recognition exhibiting local image sampling, a self-organizing map neural network, and a hybrid convolutional neural network. The self-organizing map provides a quantization of the image samples into a topological space where inputs that are nearby in the original space are also nearby in the output space, thereby providing dimensionality reduction and invariance to minor changes in the image sample, and the hybrid convolutional neural network provides for partial invariance to translation, rotation, scale, and deformation. The hybrid convolutional network extracts successively larger features in a hierarchical set of layers. Alternative embodiments using the Karhunen-Loeve transform in place of the self-organizing map, and a multi-layer perceptron in place of the convolutional network are described.

Abstract: Optical components that are designed to be coupled together in modular fashion to form an optical network. The components are shaped so that a plurality of components can be coupled together to form a light cube. The components are provided with mating means to permit easy coupling. The preferred form of component is a right-angled triangular prism that can be coupled together with a similar prism to form a cube.