Abstract: To make an overclad fiber optic coupler, the bare regions of a plurality of optical fibers are positioned within a glass capillary tube. The midregion of the tube is then collapsed and stretched to cause coupling between the fibers. To obtain desirable coupling characteristics, the fibers must be situated in the glass tube bore in side-by-side fashion such that the cross-sectional configuration of the fibers constitutes a given geometrical array. To ensure that the fibers are properly positioned within the glass tube, they are fed to that tube from a plurality of guide tubes, the ends of which are retained adjacent to the end of the glass tube in side-by-side fashion in the given geometrical array.

Abstract: Type-specific capsular polysaccharide preparations from Streptococcus pneumoniae, having on average less than about 1000 oligosaccharide repeat units per molecule, polydispersities between 1.0 and 1.4, intrinsic viscosities between 0.6 and 3.0 dL/g, and less than 3% contamination of type-specific polysaccharide by group-specific C-polysaccharide, are produced by a novel process. The novel type specific polysaccharide products are useful in the preparation of vaccines, especially covalent conjugates comprising the novel polysaccharide linked to a T-cell stimulatory carrier protein. Vaccines comprising the novel polysaccharides are useful in the prevention of infection and of diseases associated with infection by Streptococcus pneumoniae.

Abstract: An apparatus and method for transmitting and receiving signals includes an analyzer, for decomposing an input signal into a plurality of signals with each one of the plurality of signals occupying one of a corresponding plurality of channels and a synthesizer, having a plurality of channels with each channel adapted to receive one of the plurality of analyzer signals, for combining the plurality of signals to reconstruct the input signal.

Abstract: A compact monolithic interferometric switch such as a Mach-Zehnder switch is formed such that one of the waveguide paths between the input and output couplers contains a material having exhibits a resonant nonlinearity, whereby its refractive index changes when pump power propagates through it. Each of the waveguide paths has a different propagation constant whereby signal light is subjected to a different delay in each path when no pump power is propagating through the rare nonlinear path. An input signal applied to the input of the switch appears at a first output terminal when the pump power does not propagate through the nonlinear path, and it appears at a second output terminal when the pump power is applied to the nonlinear path. Switching occurs at relatively low levels of pump power.

Abstract: A divergent flap seal for a gas turbine engine exhaust nozzle having a longitudinal axis is provided, having a body, a spine member, and a flap position guide. The flap position guide separates adjacent divergent flaps regardless of the angle the flaps are skewed relative to the longitudinal axis of the nozzle, thereby more evenly distributing the flaps about the circumference of the nozzle.

Abstract: An apparatus and method for transmitting and receiving signals includes an analyzer, for decomposing an input signal into a plurality of signals with each one of the plurality of signals occupying one of a corresponding plurality of channels and a synthesizer, having a plurality of channels with each channel adapted to receive one of the plurality of analyzer signals, for combining the plurality of signals to reconstruct the input signal.

Abstract: An M.times.O multiplex/demultiplex device is disclosed. An M.times.N coupler is connected to an N.times.O coupler by phase shifting means. The phase shifting means provide N paths between the couplers, each path having an optical path length different from every other optical path length. The coupling region of the M.times.N coupler must provide for substantially uniform division of light power among the coupler branches when M are the launch ports. Similarly, the coupling region of the N.times.O coupler must provide for substantially uniform division of light power among the coupler branches when O are the launch ports. A preferred embodiment includes two fused waveguide fiber couplers with dissimilar waveguide fibers used as the phase shifting means.

Abstract: A novel conjugate vaccine comprising partially hydrolyzed, highly purified, capsular polysaccharide (Ps) from Streptococcus pneumoniae bacteria (pneumococci, Pn) linked to an immunogenic carrier protein, is produced by a new process. The conjugate is useful in the prevention of pneumococcal infections. Vaccines comprising a mixture of from one to ten different pneumococcal polysaccharide-immunogenic protein (Pn-Ps-PRO) conjugates induce broadly protective recipient immune responses against the cognate pathogens from which the polysaccharide components are derived. Young children and infants younger than 2 years old, normally unable to mount a protective immune response to the Pn-Ps alone, exhibit protective immune responses upon vaccination with these Pn-Ps-PRO conjugates.

Abstract: A method for interconnecting electrical system components. A leadframe (10) having leads (11) is encapsulated within a molding compound to form a first section (36) of the interconnect package (35). The first section (36) optionally includes channels (54). A leadframe (20) having leads (22, 23) is encapsulated within a molding compound to form a second section (37) of the interconnect package (35). The first and second sections (36 and 37, respectively) are coupled together with an adhesive material (43). An end (44) is removed from the interconnect package (35) forming an edge (50). A bare semiconductor chip (51) is coupled to the edge (50).

Abstract: An interconnect package (35) for interconnecting electrical system components. A first leadframe (10) having leads (11) is encapsulated within a molding compound forming a first section (36) of the interconnect package (35). The first section (36) optionally includes channels (54). A second leadframe (20) having leads (22, 23) is encapsulated within a molding compound forming a second section (37) of the interconnect package (35). The first and second sections (36 and 37, respectively) are coupled together with an adhesive material (43). An end (44) is removed from the interconnect package (35) forming an edge (50). A semiconductor chip (51) is coupled to the edge (50).

Abstract: A laser generator and a receiver are used to transmit and receive a laser beam for reflection by the leading edge of existing printing on ware to establish an indexing reference for printing to be newly applied to the ware. The receiver provides an electrical signal to disconnect drive motor from a drive train and engage a non-operating screen drive train to stop rotation of the ware. After indexing has been accomplished, the printing cycle is initiated causing silk screen to reciprocate in a synchronous speed with rotation of the ware while a squeegee establishes line contact with a screen to force printing medium through open spaces on the screen onto the ware.

Abstract: Microbridge formation in chemically amplified negative tone photoresists based on poly(hydroxystyrene) (PHS) is avoided when the PHS is blended together with a co-polymer of PHS and an acrylic polymer such as poly(methyl methacrylate) (PMMA). The blend should include at least 10% by weight of the co-polymer. In operation, hydrogen bonding between the hydroxystyrene sub-units and the methacrylate sub-units decreases the availability of sites for crosslinking, and this reduction in crosslinking sites makes the blend less susceptible to formation of polymer resist microbridges. The invention is practicable with a polymers having a wide range of molecular weights (2000-50000 daltons), and development can be achieved using the industry standard 2.38 wt % trimethylammonium hydroxide (TMAH) developer without any adverse impact on the photoresist.

Abstract: A fiber optic coupler is formed by inserting a plurality of optical fibers into the longitudinal bore of a glass tube so that at least a portion of each fiber extends from at least one end of the tube. The midregion of the tube is collapsed onto the fibers, uncollapsed bore portions remaining at the tube end regions. Each bore portion is connected to the tube end surface by a funnel that facilitates the fiber insertion step. The central portion of the midregion is stretched to reduce the diameter thereof. In a first embodiment, glue is applied to the funnel. Before the glue is cured, a sufficient period of time is allowed to elapse to permit said glue to flow by capillary action between the fibers and the adjacent portion of the wall of the bore portion. The glue flows at least 3 mm into the bore portion beyond the bottom of the funnel. The glue that flows by capillary action fails to completely surround the fibers with glue. The glue is then cured.

Abstract: An apparatus and method for transmitting and receiving signals includes an analyzer, for decomposing an input signal into a plurality of signals with each one of the plurality of signals occupying one of a corresponding plurality of channels and a synthesizer, having a plurality of channels with each channel adapted to receive one of the plurality of analyzer signals, for combining the plurality of signals to reconstruct the input signal.

Abstract: A 1.times.N fiber optic coupler is formed by assembling a coupler preform including spacer tube means surrounded by an outer glass tube that is concentric with the spacer tube means. A first optical fiber is disposed in an axial bore in the spacer tube means, and N optical fibers are disposed within a gap between the spacer tube means and the outer tube, the first fiber and the N fibers extending through the midregion of the coupler preform. The midregion of the outer tube is heated to collapse it about the fibers, and the central portion of the midregion is stretched to reduce the diameter thereof over a predetermined length. In accordance with the invention, the spacer tube means is glued to the first optical fiber and to the outer tube.

Abstract: An optical system for coupling a laser radiation source to a circularly symmetric single-mode optical fiber. The laser radiation source produces a beam of light having an elliptical mode field. The input end of a coupling fiber, which has a core that is elliptically-shaped in cross-section, is situated in light receiving relationship with respect to the source. The coupling fiber is oriented with respect to the source such that the mode field of the source is aligned with the coupling fiber core to provide the most efficient coupling of light from the source to the fiber. Means such as an evanescent coupler couples light from the output end of the fiber to the circularly symmetric fiber.

Abstract: A Mach-Zehnder filter includes an input coupler for splitting an input signal into N equal output signals, where N>2, and a signal combining coupler for combining N optical signals into a single output signal. It further includes N optical waveguide fibers for connecting the N outputs from the input coupler to the signal combining coupler. Each of the N optical fibers subjects the light propagating therethrough to a delay that is different from the delay experienced by light propagating through each of the other optical fibers. This Mach-Zehnder filter exhibits greater finesse per stage than previous Mach-Zehnder devices, finesse being the ratio of the wavelength separation between adjacent peaks to the peak widths.

Abstract: A low loss fiber optic coupler of the type wherein a plurality of single-mode optical fibers are fused together along a portion of the lengths thereof to form a coupling region. Each fiber includes a core and a cladding, the lowest refractive index of the fiber claddings being n.sub.2. Each of the output fibers of the coupler further includes a surface region of refractive index n.sub.4 that inhibits the coupling of light to lossy composite modes, n.sub.4 being lower than n.sub.2.

Abstract: A monolithic, environmentally stable Mach-Zehnder device is formed by threading first and second dissimilar optical fibers through the bore of a glass tube. The tube is evacuated and heated to collapse it onto the fibers. The tube is further heated and stretched at two spaced locations to form two couplers that are joined by the two optical fibers. The fibers have different propagation constants in the region between the two couplers, whereby there is a relative delay in the optical signal propagating in one of the fibers with respect to the optical signal propagating in the other fiber.

Abstract: After a plurality of optical fibers are fused to make a fiber optic coupler, the ends thereof are glued to a substrate to provide the outwardly extending fibers with adequate pull strength. The glue can flow from the point of application toward the fused region where it can adversely affect the the device. To prevent the glue from flowing too far toward the fused region and yet permit sufficient flow to strengthen the fibers, a beam of UV light is directed onto the fibers at that predetermined point where glue flow should stop. When the glue is cured by the beam, it stops flowing. Thereafter, the remainder of the glue is cured.