Abstract: A tunable external cavity laser equipped with an optical path length compensator for adjusting an optical path length of the cavity, a wavelength selector for selecting an operating wavelength of the light in a single longitudinal mode and a dispersion compensator for compensating a dispersion of the light. In order to achieve mode-hop-free tuning the laser has a synchronizer for synchronizing the optical path length compensator, the wavelength selector and the dispersion compensator to maintain the light in the selected single longitudinal mode while the wavelength selector tunes the operating wavelength. The laser employs a pair of prisms and a wedge filter or a gap filter to perform the functions of the optical path length compensator, the wavelength selector and the dispersion compensator.

Abstract: Methods and apparatus for modifying membranous tissue, growing cells on modified membranous tissue, and for transplantation of modified tissues and modified tissues with attached cells are provided. In particular, the invention provides methods and apparatus for modifying membranous tissue such as lens capsule tissue and inner limiting membrane tissue, for growing cells such as iris pigment epithelial (IPE) cells and retinal pigment epithelial (RPE) cells on modified membranous tissue, and for modifying membranous tissue and growing cells on biodegradable polymer substrates. A method of modifying membranous tissues comprises depositing micropatterns of biomolecules onto membranous tissue with a contacting surface such as a stamp; other methods include mechanical ablation, photoablation, ion beam ablation, and modification of membranous tissues via the action of proteolytic enzymes.

Abstract: An implantable miniaturized pressure sensor integrates a capacitor and an inductor in one small chip, forming a resonant LC circuit having a Q value of 10 or greater. The capacitor has an upper capacitor plate and a lower capacitor plate disposed proximate thereof. The upper and lower capacitor plates are connected to one or more spiral inductor coils. The sensor is micromachined from silicon to form a thin and robust membrane disposed on top of the upper capacitor plate. The sensor is hermetically sealed and the membrane is deflected relative to the upper capacitor plate by an external fluid, gas, or mechanical pressure. The resonant frequency of the sensor can be remotely monitored and continuously measured with an external detector pick up coil disposed proximate the sensor. The sensor can be smaller than 2×2×0.5 mm and is particularly useful for intraocular applications.

Abstract: Interference reduction with a current-mode transversal filter having taps including binary current sources is provided. Each binary current source provides an output current having either of two distinct values, depending on a binary input. The product of a tap coefficient and an interference data signal value is obtained by independently generating the contribution from each interference data bit using a binary current source and providing these contributions to a current summing junction. Binary current sources can be implemented in analog, digital, or mixed-mode circuitry. Echo, near end cross talk, and far end cross talk are examples of interference that can be reduced in this manner. The use of binary current sources provides significant flexibility, especially in connection with multilevel modulation schemes such as pulse amplitude modulation (PAM).

Abstract: Method and apparatus for reducing radio frequency interference (RFI) using a dual-element patch antenna [10]. The antenna possesses two antenna elements [13, 14] having distinct radiation patterns. Either element may be independently selected using a DC bias voltage. Diodes [20] connected to the elements serve to disable one element when the other is selected. In one selected mode, a nominal radiation pattern provides a broad, hemispherical shaped sensitivity that is designed for acquiring and tracking all navigation satellites above the horizon. This nominal radiation pattern, however, is susceptible to interference that is present near or below the horizon. The second selectable radiation pattern of the dual-element antenna has comparatively higher gain toward zenith, and lower gain at and below the horizon to mitigate interference. This combination of features is packaged in a single antenna unit that can be a direct replacement for existing antennas.

Abstract: A method and a nonlinear frequency mixer employing the method to generate at least one output light from at least one input light with the aid of a quasi-phase-matching (QPM) grating for quasi-phase-matching the input and output light involved in a nonlinear frequency mixing operation such as three-wave mixing, four-wave mixing or other nonlinear operation mediated by a susceptibility of the nonlinear optical material. The QPM grating has a beam-modifying pattern with features for wave front shaping. More specifically, the features shape the wave fronts of the output light by diffraction or phase front shaping to thereby modify its propagation. This modification of propagation can be used to steer, focus, defocusing, split and/or collimate the output light.

Abstract: A compact safety cone that can self-right when in use and be reduced to a compact size when not. The compact safety cone has a base, flexible means, and cover. The spring flexible means coils around the center of the base in decreasing diameters without overlapping. The compact safety cone has a substantially low center of gravity due to the weight distribution among its components. By design, the compact safety cone has a fast impulse response to direct (contact) and indirect (no-contact) perturbations and is capable of being run over or hit by a vehicle and “self-right” substantially immediately after the impact. When not in use, an integrated holding means conveniently and securely keeps the flexible means to the base. The holding means can be, e.g., a cover, lid, light, sign, mirror, box, case, hook, latch, strap, Velcro, pin, lock, etc. In some cases, an optional handle may be included.

Abstract: A system and method are provided for developing a database of body surface ECG P-wave maps for classification and localization of left-sided atrial arrhythmias. The system and method include generating and receiving P-wave data in a subject by left atrial pacing or receiving P-wave data in a subject during spontaneously occurring or induced left atrial arrhythmias; computing (e.g. potential or integral) maps of the P-wave data; classifying the maps specific to a left atrial ectopic origin; verifying the classification procedure; averaging the classified maps into mean maps; and storing and accessing the mean maps in the database. The mean maps of the P-wave data in the database can be used to automatically classify and localize P-wave data from a patient obtained during a left atrial arrhythmia such as atrial tachycardia, focal atrial fibrillation, or orthodromic atrioventricular reentrant tachycardia.

Abstract: An exchange-coupled magnetic structure of a cobalt-ferrite layer adjacent a magnetic metal layer is used in magnetorestive sensors, such as spin valves or tunnel junction valves. The exchange-coupled magnetic structure is used in a pinning structure pinning the magnetization of a ferromagnetic pinned layer, or in an AP pinned layer. A low coercivity ferrite may be used in an AP free layer. Cobalt-ferrite layers may be formed by co-sputtering of Co and Fe in an oxygen/argon gas mixture, or by sputtering of a CoFe2 composition target in an oxygen/argon gas mixture. Alternatively, the cobalt-ferrite layer may be formed by evaporation of Co and Fe from an alloy source or separate sources along with a flux of oxygen atoms from a RF oxygen atom beam source. Magnetoresistive sensors including cobalt-ferrite layers have small read gaps and produce large signals with high efficiency.

Abstract: A new and useful updating tool is provided for indexing electronic text in a highly integrated electronic text indexing and search system. The integrated system encompasses a concept model, a query model, an enhanced markup tool, a user interface, and a search engine. A domain expert utilizes the integrated system to efficiently and effectively indexing electronic text for precise and fast retrieval by a search engine. The updating tool aids the indexing process as a consequence of changes in the query model, to an indexed document, or both. The updating tool comprises a document change tool and a query model change tool as well as an enhanced markup tool and an enhanced query model tool. The updating tool guides the domain expert by suggesting which indices need to be updated and flags index entries that need to be removed.

Abstract: A CMOS DPS image sensor architecture for improving SNR and dynamic range is presented. The CMOS DPS architecture includes self-reset digital pixels capable of collecting more charge than the physical well capacity. A method for improving SNR without reducing dynamic range in a CMOS video sensor system under low illumination is described, wherein the CMOS video sensor system employing self-reset DPS architecture includes pixel level A/D conversion and wherein each DPS pixels is capable of resetting itself whenever a corresponding diode reaches saturation during integration time.

Abstract: A planar 2×2 switch is provided for controllably coupling first and second input channels to first and second output channels. The switch includes a first reflector that is movable between a first position and a second position. When the first reflector is in its second position, it reflects light from the first input channel to the second output channel and reflects light from the second input channel to the first output channel. When the first reflection is in its first position, it does not affect the optical beams in the switch. Instead, these beams are reflected by a second reflector which has two reflective surfaces. The second reflector reflects light from the first input channel to the first output channel and reflects light from the second input channel to the second output channel. Switches having a larger number of input and output channels are also provided.

Abstract: The present invention provides a word voter for redundant systems with n modules wherein each of these n modules generates a word output. The word voter receives word outputs from each of the n modules. A voter decision is generated by the word voter utilizing a word basis of the word output of each of the n modules. The voter is based on a majority voting principle. The advantage of the present invention is that the word voter can be used to design redundant systems, such as, but not limited to, TMR systems, that are protected against common mode and multiple output failures. In addition, another advantage of the present invention is that is provides for a technique to efficiently design a TMR simplex system. The present invention provides a word voter for hardware systems.

Abstract: A fiber amplifier in a depressed cladding or W-profile fiber. The fiber has a core doped with the active material and defined by a core cross-section and a refractive index no. A depressed cladding of index n1 surrounds the core and a secondary cladding of index n2 surrounds the depressed cladding. The fiber amplifier is pumped to a level of high relative inversion, such that the active material exhibits positive gains in a short wavelength band and high gains in a long wavelength band. The core cross-section, the depressed cladding cross-section and the refractive indices no, n1, and n2 are selected to obtain a roll-off loss curve about a cutoff wavelength ?c. The roll-off loss curve yields losses at least comparable to the high gains in the long wavelength band and losses substantially smaller than the positive gains in the short wavelength band.

Abstract: An optical communication system such as a Wavelength-Division-Multiplexed (WDM) or Dense Wavelength-Division-Multiplexed (DWDM) communication system using Erbium doped fiber amplifiers (EDFAs) for amplifying signals in the S-band. The fiber amplifier has a core doped with Erbium and defined by a core cross-section and a refractive index n0. The fiber amplifier has a depressed cladding surrounding the core and a secondary cladding surrounding the depressed cladding. The depressed cladding has a depressed cladding cross-section and a refractive index n1, and the secondary cladding has a secondary cladding cross-section and a refractive index n2. The fiber amplifier has a pump source for pumping the Erbium to a level of high relative inversion D such that the Erbium exhibits positive gains in the S-band and high gains in a long wavelength band longer than the S-band, i.e., in the C- and L-Bands.

Abstract: The invention provides a plug-and-work sensor interface device named “puck” for fast and easy deployment of various types of serial devices, which include commercial off-the-shelf and custom-made sensors and instruments, in a distributed, dynamic oceanic observing network. In an embodiment, each puck is removably attached and electrically coupled to a specific sensor to be deployed. The puck comprises a non-volatile memory for associating and storing arbitrary binary information about the sensor and a microprocessor for controlling how the information is read from and written into the non-volatile memory. The sensor information may include unique sensor identifier, sensor metadata, sensor device driver, etc. The puck itself does not execute any of the device code; rather, a host retrieves the sensor information from the puck when the puck is plugged in. The retrieval can be done automatically or semi-automatically with user interaction.

Abstract: An optical circulator has a first collimator; a first block of birefringent material; a first compound polarization rotator; a light angle deflector (e.g., Wollaston prism); a second compound polarization rotator; a second block of birefringent material; and a second collimator. Light from the first fiber exits the first collimator along a first path into a first collimated beam that first hits the central plane on a crossing line between the interface and the central plane such that the first collimated beam exits the light angle deflector along a second path substantially parallel to the longitudinal direction and is received by the second fiber. Light from the second fiber exits the second collimator along the second path into a second collimated beam that exits the light angle deflector along a third path and is received by the third fiber.

Abstract: A resource allocation method for use in a wireless ATM network comprises receiving on a wireless signaling channel a request for access to a shared frequency-time sliced wireless medium. A channel matrix is then searched for a set of available frequency-time slots. The channel matrix represents a time frame within the shared frequency-time sliced wireless medium, and is used to keep track of resource allocation in the time-frequency sliced medium. The set of available time-slots is then allocated if the allocation does not violate a frequency switching constraint, and if the set of available frequency-time slots contains a number of slots no smaller than a requested number of slots. In a preferred embodiment of the invention, the searching step uses a greedy resource allocation strategy to search a channel-chunk matrix comprising a list of contiguous chunks of available time slots in each frequency of the shared frequency-time sliced wireless medium.

Abstract: A method is provided for determining the positional accuracy of leaves of a multileaf collimator for delivering doses of radiation to a particular spatial location for treatment purpose. The method could be implemented as routine quality assurance check of the multileaf collimator leaf positioning errors. The method includes producing a first field and producing a second field, which is different from the first field. A dosimeter means is included for measuring a radiation dose difference or ratio between the first field and the second field at at least one spatial location. The dose difference or ratio is then used to determine the positional accuracy of the leaves by comparing with a known relationship between leaf positional errors and relative dosimeter outputs. The method provides a more simplified, accurate, efficient and reliable method over currently used methods.