Abstract: A predistortion circuit and method provides signals to oppose and cancel an anticipated phase and frequency distortion in a coupled electrical system. The predistortion circuitry includes first and second subcircuits which include opposing diodes, providing 180 degree out-of-phase and in-phase signals to produce second, third and higher order predistortion outputs.

Abstract: A method of forming a tap into an intermediate point on a continuous coaxial cable, and a coaxial cable tap housing suitable for forming such a tap. The tap housing includes a recess and an alignment element having a predetermined spatial relationship with the recess. The recess has an entry, an exit and a passage connecting the entry and exit. When the tap housing is fixed to a cable, the exit of the recess is closer to the outer conductor of the cable than the entry of the recess is to the outer conductor. The alignment element is used to position a cutting tool which is inserted through the entry of the recess to form an opening in the outer conductor and a cavity in the dielectric under the opening. A tap insert, which includes a coupler assembly, is mounted to the housing, and the coupler assembly is inserted through the entry of the recess and through the opening into the cavity formed in the cable. In specific embodiments, the recess and opening are elongated.

Abstract: An optical isolator system and method improving the manufacturability of the system, including fabricating a unitary tubular optical isolator system in two parts which are soldered together. The tubular system includes an internal disk to protect the isolator from heated solder during joinder of containment portions. The optical isolator system includes tubes to space polarizer, analyzer, and isolator portions.

Abstract: An optical fiber water sensor includes a mandrel having a convex or concave shape adjacent to an optical fiber which is adjacent to a water swellable material held in a reservoir. Upon coming in contact with water, the material swells and deforms a section of the optical fiber about a contour defined by the mandrel thus attenuating a signal propagating through the fiber which is detected by an optical detector to indicate the presence of water.

Abstract: An optical receiver includes a photodetecting device and a wide band video amplifier. The photodetecting device and the video amplifier are coupled by reactive elements which are selected to provide a highly linear and highly sensitive response over a frequency range of approximately 400-950 MHz. The crosstalk between two signals are ten parts per billion when the laser power is at 1 milliwatt and modulation is 25 percent per signal. The noise generated by the receiver is only equivalent to 6 billionth of an ampere. The receiver uses commerically available components.

Abstract: An optical fiber read or write tap includes a substrate having a substantially flat upper surface on which two separated grooves are formed, a light element being disposed in the second groove so as to be capable of coupling light with a bent portion of an optical fiber disposed in the first groove.

Abstract: A method of aligning an optical signal source and a waveguide which comprises; directing the signal into the waveguide, monitoring the intensity of the signal backscattered along the waveguide, and altering the relative positions of source and waveguide in response to said intensity.

Abstract: An apparatus for injecting light into or withdrawing light from an optical fiber using a resiliently deformable material includes a hard transparent member disposed in contact with a surface of the resiliently deformable material in a vicinity of a light element which minimizes material creep of the resiliently deformable material in a vicinity of the light element which stabilizes a coupling and decoupling efficiency with an optical fiber.

Abstract: An article suitable for use in the adhesive joining of two optical fibers with low light loss comprises a tubular container an inner surface of which is coated with a release agent and/or is composed of an inherently releasing material, which is larger in cross-section at the ends than at a central region, the smaller central region being where the ends of the fibers are joined.

Abstract: An optical coupler for withdrawing light from an optical fiber includes first and second movable members on which are mounted a plurality of bending posts offset longitudinally relative to one another. A retaining post, offset longitudinally from the bending posts, has a groove therein so that an optical fiber can be wrapped therearound. Thereafter, the first and second members are moved towards each other such that the bending posts interleaf and bend the optical fiber in a plurality of positions causing light to be emitted from the optical fiber at bent portions thereof, which light is detected by optical detectors located behind the bending posts.

Abstract: A method and apparatus for determining a dB loss across an optical fiber splice includes the steps of determining a first maximum detected optical signal when the fiber ends are moved relative to each other in a X direction, determining a second maximum optical signal when the fiber ends are moved relative to each other in a Y direction, determining a third optical signal when the fiber ends are optimally substantially aligned, determining a fourth optical signal when subsequent to the fiber ends actually being secured to each other.

Abstract: A method and apparatus for determining optical power attenuation across a splice between first and second optical fibers utilizes the algorithm:dB=10 log (1-L.sub.tel) (2)where L.sub.tel is determined by compensating for differences in intensity profiles existant in the first optical fiber when injecting light therein for purposes of measuring attenuation versus the intensity profile created when injecting light into the first fiber for transmitting telecommunications data and the light has been propagating in the fiber for a distance and steady state intensity distribution is achieved. Preferably, a numerical aperture of the first optical fiber and a sample optical fiber are empirically determined, and L.sub.tel is calculated by compensating for differences between these numerical apertures.

Abstract: This invention provides a method and apparatus for making certain measurements across a splice of a first optical fiber and a second optical fiber, then calculating the actual decibel attenuation across the splice for optical signals transmitted through the fibers during actual use. The method of this invention involves measuring the optical power P.sub.2 in the second fiber with the fiber ends separated longitudinally a certain distance, then measuring the optical power P.sub.1 in the second fiber with the fiber ends positioned close together for effecting the splice. The attenuation is calculated from the formuladB=10 log(P.sub.1 /RP.sub.2)where R is a predetermined constant for the fibers being spliced.