Abstract: A set of Diffie-Hellman data encryption values is generated prior to receiving a request for the data encryption values. The data encryption values are then stored in a database. The generating and storing steps are performed repeatedly thus creating a stored table of data encryption values in the database. When a new user calls to activate a mobile station, a cellular network can select from among precalculated Diffie-Hellman data encryption values immediately transmit the values to the mobile station.

Abstract: A method for selecting one of a plurality of line identification (ID) databases for validation of an operator-assisted call billed to a ported directory number account comprises determining whether billing information received from a caller is directory number-based. If the billing information is directory number-based, an operator services system (OSS) queries a number portability database to retrieve available routing information associated with billing information provided by the caller. The routing information is used to access a billing acceptance database which stores a list of those service providers which allow the OSS to access their customer data. If the OSS is able to access an identified service provider's data, the routing information received from the number portability database is used to route a billing validation request to a selected one of the plurality of line ID databases.

Abstract: A computer-based file system enables user access to any of a plurality of previously-stored data files, each file being identified by at least two file names formatted using different file name formats. The system receives a user request including a purported file name having one or more appended segments and a base name, at least one of said appended segments being used to identify the file name format of said base name. The system then checks file names which utilize the identified file name format to locate a data file of the previously-stored data files having a file name which is the same as said base name. According to another feature, data files are identified using one file name format from which the system compiles a file name using the file name format identified in the appended segment. The base name is then compared against the computed file names to locate the desired base name file.

Abstract: An optical communication system is disclosed including an all-optical device whose output modulated optical beam is locked to an input modulated optical beam. In a specific embodiment of the system, the device may be a self-electro-optic effect device (SEED), which is operated as an oscillator by means of an associated tank circuit. Such an embodiment permits recovery of a clock frequency from a bit stream which is input into the device. When the output of the device is directed into an optical decision element, an all-optical regenerator may be realized.

Abstract: A wavelength tunable optical filter having a characteristic single transmission peak for enhanced tunability comprises a phase control section positioned between a Distributed Bragg Reflector section and a high reflectivity mirror. The Distributed Bragg Reflector section comprises a periodic region grating positioned over an end portion of a passive waveguide whereas the phase control section comprises the portion of the passive waveguide region located between the grating and the mirror. Continuous tunability in the range of several THz may be achieved by controlling the refractive index in either the phase control or distributed Bragg reflector section. The optical filter is expected to have a frequency switching time of a few nanoseconds and, thus, is applicable to both transmission and switching applications.

Abstract: An improved optical amplifier is disclosed with reduced signal-induced, deleterious, nonlinear effects, such as crosstalk, inter-modulation distortion and other saturation-induced effects. The invention comprises an optical amplifier with a compensation loop, such as a feed-forward or a feed-backward loop. This loop provides additional pumping to the gain medium associated with the amplifier, thereby compensating for what would otherwise be deleterious, signal-induced variations in the gain of the optical amplifier.

Abstract: A new self-aligned contact technology is afforded by semiconductor devices having a digitated electrode and a contiguous conductive region that contact first semiconductor regions and second semiconductor regions, respectively. The first semiconductor regions and the second semiconductor regions are formed in a semiconductor substrate, with each second semiconductor region underlying a finger of the digitated electrode. Advantageously, by forming a contiguous conductive region over the first semiconductor regions located between the fingers of the digitated electrode, it is not only possible to contact second semiconductor regions with a common electrode, but also to self-align the common electrode with the digitated electrode. Ohmic shorting between the digitated electrode and the contiguous conductive region is afforded by interposing an insulating region therebetween.

Abstract: An optical communication system in which a group, or "comb", of intelligence-bearing signals are frequency-division-multiplexed and stabilized using a corresponding "comb" of resonances associated with a Fabry-Perot cavity.

Abstract: A novel fabrication method is disclosed for fabricating a bipolar transistor having a digitated emitter electrode and a contiguous polysilicon region acting as a self-aligned base contact. The process substantially reduces the parasitic capacitances as well as eliminates the need for the intrinsic base region to be exposed to multiple etching, which results in the fabrication of small and reproducible base widths.A first polysilicon layer is deposited over the surface of a semiconductor substrate and, then, implanted with base dopants, which are driven into the surface of the active region by a furnace process for forming an intrinsic base region. Emitter dopants are next implanted into the first polysilicon layer. Subsequently, a nitride layer is deposited and the digitated emitter fingers patterned by selective etching.

Abstract: An optical intersection with reduced transmission loss is described. An embodiment of the inventive interconnection comprises two intersecting waveguides. According to the teachings of the invention, deleterious asymmetric field distortions in the waveguides, associated with the presence of the adjacent waveguides, are reduced by, for example, changing the width of the intersection region, and the widths of the waveguides as they approach the intersection region.

Abstract: An improved semiconductor optical amplifier with shortened gain-recovery time is disclosed. In the inventive device a carrier-storage region is placed adjacent to the gain region of the amplifier. Passage of carriers from the storage region to the gain region rapidly replenishes the carrier population within the gain region, thereby permitting rapid recovery of the amplifier gain.

Abstract: A switching system is described in which routing information, which may be associated with packets originating in cellular calls, is divided into information which does not change as the subscriber crosses a cell boundary, and information which does change as the subscriber crosses a cell boundary. Routing procedures associated with the information which does not change as the subscriber crosses a cell boundary are established and stored in the memory of the switch at the beginning of the call. However, routing procedures associated with the information which does change as the subscriber crosses a cell boundary may be derived from the header information of each packet as it arrives at the appropriate portion of the switch.

Abstract: An efficient N.times.N star optical coupler suitable for mass production in integrated form is disclosed. The coupler can be realized using silicon technology to form a dielectric coupler slab and two arrays of strip waveguides all on a single glass substrate. Power transfer betwen the two arrays is accomplished through radiation in the dielectric slab with theoretical efficiency exceeding 30% under optimized conditions.

Abstract: A grating coupler is combined with a quantum well index modulator and an optical waveguide to alter the reverse or forward coupling characteristics between two different propagation modes of the system.

Abstract: An optical power tap is disclosed which allows effectively nonreciprocal injection and removal of power at each node of a single-mode optical fiber local area network. The power tap uses a wavelength-selective directional coupler to inject and remove power from the bus, and a nonlinear converter in the bus to convert light from one wavelength to another. In the specific embodiment disclosed a neodymium-doped silica fiber is used as a nonlinear material to convert light from one wavelength to another.

Abstract: This invention is a new type of Fabry-Perot cavity, and an optical communication system using such a cavity. The inventive Fabry-Perot cavity comprises both a waveguiding portion and a nonwaveguiding portion. In this manner, tunable cavities of desirable mid-range length, necessary to obtain required free spectral ranges, may be fabricated with minimal diffraction losses otherwise associated with cavities of such length. The cavity length may be varied using, for example, piezoelectric elements, and the various cavity elements may be aligned and connected, using fiber connector technology.

Abstract: A practical, manufacturable Fabry-Perot etalon and method for fabricating the same is disclosed. The plastic coating material is removed from the ends of a predetermined length of single mode fiber. A small area of the glass fiber is exposed by scraping away the coating near the center of the fiber on one side, and the fiber is then broken at this point forming a small gap. The remaining coating holds the broken fiber together and automatically matches the pieces in alignment. Mirrors of desired relfectivity are applied to the polished fiber ends, either by gluing on discrete mirrors or by applying multilayer dielectric coatings. The fiber/mirror structure is mounted onto a piezoelectric substrate. A voltage is applied to the piezoelectric substrate, causing longitudinal expansion of the fiber gap and providing the scanning means to obtain a spectrum of resonant wavelengths.

Abstract: High-silica glasses are formed by sintering a dried gel at temperatures below the liquidus. The gel may be formed by mixing colloidal silica particles or silica-containing liquids with appropriate liquids. Fragmentation of the gel during drying is advantageously avoided by redispersing the dried gel or sol in a liquid to yield a colloidal suspension which is then gelled, dried, and finally sintered below the liquidus.

Abstract: This invention involves optical fiber which supports essentially only a single guided mode, perhaps degenerate, at the transmission wavelength, usually between 0.6 and 1.7 microns. The index of refraction of the core material is graded in the radial direction so as to yield an optical fiber with very low total dispersion and therefore high bandwidth. Specific embodiments include, in addition to the low dispersion characteristic, improved field confinement, and therefore permit lower clad-to-core ratios then heretofore believed practical. Additional advantages which accrue as a result of the greater field confinement include lower cabling, microbending, and curvature-induced losses.

Abstract: A method of coating uncoated portions of a coated optical fiber is disclosed. In this method a grooved split mold apparatus is used. This fiber, including coated portions of the fiber are placed within the groove and appropriately tensioned so as to prevent contact between the uncoated portions of the fiber and the mold. Injection molding techniques are then used to recoat the uncoated portions of the fiber.