Abstract: The invention is a repeater for a telecommunications transmission system such as a CDMA wireless system. The repeater reduces leakage by using a feedback signal whose amplitude and phase are adjusted in response to the amplitude and phase of a sampled input signal when a switch turns off the normal output of the repeater for a short period of time. In one embodiment, a pilot signal is transmitted during this time period so that the sampled input is the leakage signal. In another embodiment, the sampled input is the normal transmission signal received during the time period.

Abstract: An optical amplifier achieves multistage amplification with a four port optical circulator with fiber amplifiers and Faraday rotators and mirrors connected to at least two of the ports. The fiber amplifiers permit the signal to pass through the fiber amplifiers twice.

Abstract: Disclosed is an optical component package which permits easy insertion and removal of an optical fiber termination. The termination is inserted through an aperture of a package wall and is retained within the package by a retaining clip which engages the inner surface of the wall. The termination can be removed by removal of the clip, or, in alternative designs, by a rotation of the clip.

Abstract: An active semiconductor device includes a coating comprising an oxide of tantalum and aluminum. The coating may function as an AR coating or as a passivation coating. Applications to ICs and optical devices are described.

Abstract: The invention relates to a multiwavelength add/drop multiplexer for use in an optical fiber communication system having a main optical fiber. The multiplexer includes an optical element, in the form of an optical circulator, arranged to direct substantially all of the light transmitted in a predetermined direction along the main optical fiber into a branch optical fiber regardless of wavelength. The branch optical fiber includes a transmission filter, in the form of a Fabry-Perot filter, arranged to transmit light of a predetermined wavelength and reflect the non-transmitted light back towards said main optical fiber for continued propagation along said main optical fiber. The multiplexer also includes a receiver for receiving the transmitted light, and further includes a transmitter arranged to transmit optical data signals along said branch optical fiber, through said transmission filter and towards said optical element, for propagation along said main optical fiber.

Abstract: The invention is a surge protector which can provide voltage and current protection in coaxial cable systems. The protector includes a central conductor which is coupled in series with a variable resistance, and a voltage surge arrestor which is coupled between the conductor and the housing of the protector. A capacitor may also be coupled in parallel with the resistor. The protector provides both an ac and dc signal path.

Abstract: The invention relates to an optical amplifier comprising an input and a beamsplitter connected by a first optical fiber arranged to transmit an optical signal from said input to said beamsplitter via an optical amplifying means and an optical isolator. The optical amplifier includes a second optical fiber connected between said input and said beam splitter and is arranged to transmit a second signal from said beamsplitter to said input. Preferably, the optical amplifier also incorporates an optical element which is adapted to prevent any signal from said input propagating along said second optical fiber and to prevent any signal from said second optical fiber from propagating along said first optical fiber.

Abstract: Stability of a pump laser for activating an erbium amplifier is enhanced by a grating which results in laser operation in the coherence collapse regime.

Abstract: Disclosed is a maintenance termination unit which is protected against lightening strikes and excessive currents. Resistors are placed in series with the tip and ring switches of the unit. Voltage breakdown devices, such as gas tube protectors, are coupled in a parallel with the resistors and switches.

Abstract: A building cable entrance terminal includes a panel section for supporting a number of cable connector parts to be mounted in a determined array on a panel, an entrance compartment for housing connecting portions of a number of incoming cables, and a first hinge arrangement for joining the panel section to the entrance compartment for swinging movement between a closed position where a bottom edge of the panel section is aligned with a top edge of the entrance compartment and a first major surface of the panel is enclosed by the compartment, and an open position where the first major surface is exposed to allow access to the incoming cables and connector parts mounted to stand off of the first major surface.

Abstract: Disclosed is an electrical connection system including connecting blocks and patch cord connectors where the patch cords are directed toward, rather than away from, the connecting blocks. Troughs are included between adjacent rows of connecting blocks to accommodate the patch cords from the patch cord connectors connected to one of the rows.

Abstract: Disclosed is a circuit which permits automatic switching between a main line and spare line at a subscriber's network interface device. A relay is provided between the two lines, which relay is triggered by a ringing signal on the line to be used.

Abstract: Disclosed is an electrical connector which compensates for near-end crosstalk at its mating section with near-end crosstalk of an opposite polarity and essentially equal magnitude. Conductive plates connected to the conductors provide capacitive coupling unbalance between the adjacent pairs to produce the necessary opposite polarity, equal magnitude near-end crosstalk.

Abstract: An optical amplifier having high overall gain and low gain tilt, useful in an optical transmission system or the like. The amplifier has a doped optical fiber as the amplification medium and two pumps, the shorter wavelength one propagating with the signal being amplified and the longer wavelength one propagating opposite the signal being amplified. A wavelength selective reflective fiber grating is disposed along the doped fiber to reflect the second pump signal. The addition of the grating allows the amplifier to have a higher gain with a lower gain tilt than amplifiers without the grating. Positioning the grating along the fiber allows for the control of the overall gain with respect to the gain tilt for a given fiber length.

Abstract: Disclosed is a circuit included in a channel unit for testing that channel unit in a telecommunications system. A digital signal processor detects and reproduces signals from a local digital switch and controls a number of relays which result in various terminations appearing on the channel unit. The processor then monitors the signal levels as well as the signaling bits from the channel unit to test for proper performance.

Abstract: A tunable tandem Fabry-Perot etalon in used in wavelength division multiplexed optical systems or in an optical device. One path is used to calibrate the pre-spectral range with respect to a reference wavelength and the other path is used to select and acquire the desired wavelength.

Abstract: A tunable tandem Fabry-Perot etalon in used in optical systems as a filter between two amplifier stages. The etalon filters the signal going from the preamplifier to the amplifier and provides further filtering as the output of the amplifier also passes through the etalon.

Abstract: Disclosed is a combined RF/power tap unit. The power and RF portions are provided in separate compartments with a cover for the power compartment so that access to the internal RF circuitry is possible without disturbing the power compartment. The cover for the power portion extends beyond the sides of the compartment, and the compartment includes appropriate grooves and seals to protect the wire connections from the outside environment. Detents are provided in one side of the compartment to hold the drop wires, and ribs in the cover supply strain relief.

Abstract: Disclosed is a network interface unit which comprises a multilayer modular design. The upper layer includes an array of customer bridges. The lower layer includes a splice chamber and a protector panel. The splice chamber includes openings which permit a plurality of units to be stacked. The upper layer is removably mounted to the lower layer so it can be used with existing building entrance protectors which have no interface section.