Abstract: An optical fiber transmitter comprises an optically pumped single mode MQW VECSEL for emitting an information-carrying laser beam and has an external cavity length defining a comb of optical modes, each mode corresponding to a channel wavelength of an optical telecommunications system having plural optical channels. A semiconductor structure of the VECSEL has an optical-pump-excited multiple quantum well (MQW) homogeneously broadened gain region active over a band which is less than mode-to-mode spacing, the gain region being tunable to hop from a first mode to an adjacent second mode. A tuning arrangement tunes the VECSEL from mode to mode thereby to select each one of the plural optical channels. An optical modulator adds modulation to a beam emitting from the laser to provide the information-carrying laser beam, and a coupler couples the information-carrying laser beam into an optical fiber of the optical telecommunications system.

Abstract: Apparatus for irradiating a substrate is compact, transportable, rugged, high powered, and highly efficient. It includes an improved high voltage inductor (1-230), an improved power transfer apparatus (230-294), an improved voltage multiplication apparatus (500-575), an improved auxiliary power supply (600-619) for the voltage multiplication apparatus, improved accessibility self-shielding (700), and improved methods for radiation processing of solid or liquid materials.

Abstract: A protocol for fiber-optic communication systems, or other communication systems based on transmission of unipolar pulses having wide dynamic range provides for information to be transmitted in packets having a predictable time slot for each transmitter. The receiver for such protocol has a first relatively long RC time constant mode conditioned for reception of data packets whose time of arrival is well predictable and a second relatively short RC time constant mode conditioned for reception of asynchronous randomly received packets. In the relatively long RC time constant mode, each packet includes a preamble having a first clamp interval in which no pulse is transmitted, and a second clamp interval in which a continual pulse is transmitted. A transducer on the receiver translates the packets of pulses into differential electronic signals on first and second outputs.

Abstract: A method of transmitting a broadband electrical signal to a subscriber by means of a telecommunications cable, the telecommunications cable comprising at least one pair of electrical conductors surrounded by an electrical shield, which method comprises applying the broadband signal between (a) the shield and (b) at least one of the conductors of the pair.

Abstract: The present invention provides curable gel compositions and also cured gel compositions which possess unexpectedly superior combinations of physical properties and aging resistance. These compositions are particularly useful for environmentally protecting substrates especially electrical conductors, connectors and splices and for sealing around jacketed cables, for example, where they enter splice cases.

Abstract: An article, suitable for use as a body implant, is made from a novel composition comprising a multiple phase polymer composition comprising:(a) a first phase which comprises a substantially non-hydrophilic polymeric component; and(b) a second phase which comprises a hydrophilic polymeric component;said composition (i) being capable of absorbing water to an extent that it softens with a softening ratio of at least about 2:1 and/or swells with a swelling ratio of at least about 1.3:1; and (ii) when substantially completely hydrated has an energy to break of at least about 700 N-cm/cm.sup.3 and a 2.5% Secant modulus of less than about 7,000 N/cm.sup.2.

Abstract: A method of stabilizing a poly(arylene ether ketone), which method comprises in one embodiment heating the poly(arylene ether ketone) at a temperature between about 240.degree. C. and about 325.degree. C. for a period of between about 0.5 and about 24 hours, prior to any melt-processing of the poly(arylene ether ketone) and in another embodiment hydrothermally treating the poly(arylene ether ketone) by heating it to a temperature of at least 160.degree. C. while contacting it with water.

Abstract: A process for producing an aromatic polyketone which comprises polymerizing an appropriate monomer or monomers by a Friedel-Crafts polymerization reaction using a Lewis acid catalyst. A controlling agent such as a Lewis base may be added to the reaction medium and/or the reaction is conducted under specified conditions to control the reaction. The reaction medium comprises, for example, aluminum trichloride as the Lewis acid, an organic Lewis base such as N,N-dimethylformamide or an inorganic Lewis base such as sodium or lithium chloride, and a diluent such as methylene chloride or dichloroethane. The amount of Lewis acid, the amount of Lewis base, the temperature of the reaction and the monomer to diluent molar ratio are varied depending on the monomer system to obtain melt-processable, high molecular weight, substantially linear polymers, for example poly(carbonyl-p-phenylene-oxy-p-phenylene), poly(carbonyl-p-phenylene-oxy-p-phenylene-oxy-p-phenylene), and the like.

Abstract: A shape-memory-effect actuator is provided having a shape-memory-alloy spring and a compensator spring. The alloy spring is operatively connected to a concentrically-mounted compensator spring by the use of a protective support housing which surrounds the alloy spring. The actuator includes a shape-memory-alloy spring and a compensator spring that regulates the operating conditions of the shape-memory-alloy spring to a chosen corresponding memory relaxation curve. The memory relaxation curve defines the actuator's operating stress, stroke and life.