Abstract: A coupler verification test circuit includes first and second circuits one of which is disposed at a head end of an optical fiber network and the other of which is disposed at a subscriber interface unit to be attached to the network when the head end is not operational. The subscriber interface circuit transmits instructions to a transceiver board in the subscriber interface unit for transmission to the network head end whereat the circuit thereat generates either no return signal, an acknowledgment return signal, or a default return signal. The test circuit at the subscriber interface unit then analyzes the return signal and visually indicates to a craftsman whether or not the transceiver board and other components of the SIU are operating correctly, e.g. whether or not the acknowledgement signal was returned and detected.

Abstract: A method for making a dispenser-package for holding a small quantity of fiber-optic coating material and for use in applying same to a fiber optic.The sealant or coating material is introduced into container with a hypodermic needle.

Abstract: An apparatus for terminating an optical fiber includes a resiliently deformable spherical member disposed in contact with a front end of a bore of an optical fiber contact body. Subsequent to softening an adhesive disposed within the contact body bore, an optical fiber is inserted through the bore and the adhesive until the fiber contacts the blocking member and deforms it. The resiliency of the blocking member causes adhesive to be wiped off the front face of the fiber being terminated and into an annulus formed between an outer cylindrical surface of the fiber and an inner cylindrical surface of the bore, and causes the fiber front end to be recessed a predetermined amount from a front end of the contact body.

Abstract: A tap for coupling light from an intermediate portion of an optical fiber core and a light element by passing light through a side of the optical fiber includes an optical coupler in contact with an outside surface of an optical fiber which is bent and disposed in a plane. A light reflector extending transverse to the plane deflects the withdrawn light towards the end surface of a light element disposed completely outside the plane. The tap may be used as a read tap to withdraw light, or as a write tap to inject light in optical fiber networks. A spring biased closure member urges the optical fiber to maintained in bent registration with the optical coupler within the plane. Simple tools and general craft training and knowledge may be applied to insert into, and remove the optical fiber from, the tap.

Abstract: A method and apparatus implementing the method are provided for controlling optical power output level of a laser diode modulated during a burst mode interval by digital data transitions within a shared logical bus optical communications network and over a predetermined thermal gradient. The method comprises the steps of: optically monitoring a component of the optical output power of the laser diode during each burst mode interval and converting the component into a control signal, establishing a reference signal and comparing the control signal with the established reference signal and for providing a logical condition from said comparison, generating a strobe signal from information related in time to the burst mode interval, storing the logical condition upon receipt of the strobe signal, integrating the stored logical condition over a time period to provide an integrated control signal, and regulating current flow through the laser diode in accordance with the integrated control signal.

Abstract: A tap for coupling light from an intermediate portion of an optical fiber core and a light element by passing light through a side of the optical fiber includes an optical coupler in contact with an outside surface of an optical fiber which is bent and disposed in a plane. A light reflector extending transverse to the plane deflects the withdrawn light towards the end surface of a light element disposed completely outside the plane. The tap may be used as a read tap to withdraw light, or as a write tap to inject light in optical fiber networks. A spring biased closure member urges the optical fiber to be maintained in bent registration with the optical coupler within the plane. A rail and channel is used to conveniently guide a tap closure member against the optical fiber. Simple tools and general craft training and knowledge may be applied to insert into and remove the optical fiber from the tap.

Abstract: An optical coupler for coupling light between an optical fiber core and an electrooptic transducer includes a pin and channel arrangement associated with a mechanism for opening and closing the coupler. At one position the pin engages an end of the channel whereat the coupler is open and safe insertion or removal of the fiber from the coupler is possible. At a second position, the pin engages another end of the channel and an optical fiber previously inserted into the coupler when in its open position is securely locked in the optical coupler.

Abstract: An optical fiber network includes a single mode silica core/cladding optical fiber having a cutoff wavelength in the range of about 1000-1200 nanometers, and a plurality of optical couplers serially disposed on the optical fiber so as to form a bus network, with each optical coupler injecting its own unique optical signal into the optical fiber so as to be multiplexed in time, each optical signal injected having a dominant light intensity wavelength below the cutoff wavelength of the optical fiber. Each injected signal propagates initially via a plurality of modes.

Abstract: A circuit for the transmission of optical signals, which comprises (a) a substrate which includes a waveguide through which an optical signal can pass when the system is in use; (b) an optically active device which is optically connected to the waveguide, the waveguide and the device being separated by a fluid which is transparent to the optical signal; and (c) means by which the substrate and the device are mechanically interconnected, the interconnection means allowing the substrate and the device to move relative to one another, at least in the plane which extends perpendicular to the direction in which the signal passes between the substrate and the device. Preferably, the component and the device are positioned face to face, and are interconnected by interconnection wires which extend between them.

Abstract: An inrush current limiting circuit in accordance with the principles of the present invention limits initial current flow to a highly initially reactive power load. The current limiting circuit comprises a plug in connection to a power source and two conductor paths leading from the plug in connection. A power FET has a source element to drain element path in series with one of the conductor paths and has a gate connection. A bipolar transistor is connected to shunt the gate element of the power FET to the potential at its source element when the bipolar transistor is conducting, thereby to limit the current passing through the power FET. A sense resistor is in series with one of the conductor paths for controlling a base element of the bipolar transistor to cause it to conduct when current through the sense resistor exceeds a predetermined amount.

Abstract: A bus receiver communicates with a bus head end transmitter via a communication path different from read and write optical fibers used by a plurality of remote terminals on the bus so that the bus receiver can quickly determine beginning and end of time slots, clock frequency, and signal trigger levels using a minimum amount of bits attached to a front end of each packet in each time slot.

Abstract: An optical fiber waveguide tap handling tray is provided for use with a cable containing a plurality of optical fiber waveguides which are separated from the cable and exposed in a section thereof. The tap handling tray comprises a frame, a clamp for clamping the cable to the frame adjacent the section thereof so that the exposed optical fiber waveguides are thereupon physically secured to and contained within the frame, at least one optical tap secured to the frame for engaging and bending at least one of the plurality of optical fiber waveguides against an optical coupling medium having an index of refraction selected to match the index of refraction of the optical fiber so that light energy may pass through a side of the optical fiber and through the optical coupling medium, and wherein the optical tap defines an obtuse guiding angle arranged to lie in a path with which the fiber may freely be aligned within the frame after the cable has been clamped thereto.

Abstract: A strained distributed optical fiber distribution network includes read and write optical fibers having taps attached thereto in series so as to strain portions of the fiber in excess of 0.60%, the strained portions being environmentally isolated by an enclosure which includes gel filled seals subject to a resilient load.

Abstract: An optical coupler for coupling light between a light emitter and an optical fiber includes a substrate for maintaining a bend in an optical fiber through which light can be coupled between an optical fiber core and the light emitter. The substrate includes a cavity which extends in a direction substantially perpendicular to a plane defined by the fiber bend so as to enable the light emitter to be secured to the substrate to minimize a propagation distance of light to be coupled through the substrate. The light emitter includes first and second substantially spherical lenses, one of which being disposed in the cavity so as to increase optical coupling efficiencies and result in a compact coupler design.

Abstract: A cable block for telecommunications cable includes first and second half shell members which together form a substantially cylindrical stepped longitudinal bore therethrough, portions of the bore being sealingly engaged against progressive stripped outer parts of a stripped part of the cable so as to sealingly engage against each intermediate layer thereof which could form a water channel between its adjacent cable layer. Metal pins are also provided which extend into the channel and electrically connect to a ground shield of the cable for dissipating electrical currents during current surges as can occur when lightening strikes. The cable block is useable for terminating an end of a cable of an intermediate section thereof at which access to the telecommunications conduction media is required without breaking the conduction media.

Abstract: An optical fiber connector includes first and second optical fiber contacts each of which have an end face thereof which forms a small angle with a plane which is orthogonal to a longitudinal axis of optical fibers being aligned. The small angle is chosen such that substantially all of any reflected signal at the optical fiber interface will not be transmitted back to a source generating optical signals for the optical fibers so as to reduce interference at the optical fiber source. A material of a body of the optical fiber contacts is made of a material harder than that of the optical fibers being connected so as to substantially reduce an amount of skill and attention required in grinding an end face of the optical fiber after it is disposed within a bore of the optical fiber contact body so as to result in a craft friendly installation.

Abstract: A digital phase acquisition circuit includes logic for detecting an edge of incoming data and a plurality of candidate clock phases, the circuitry further including logic for determining when the data undergoes a phase transition and at least one candidate phase which undergoes a digitally equivalent transition close in time to the data transition so as to enable the candidate phase to be used for a clock for recovering information representative of the data. The circuit allows clock to be recovered within 1 bit time of a predetermined data transition occurring, thus allowing preambles of 1 bit to be utilized in data packets.

Abstract: An optical bypass switch includes a normal state and a bypass state, a transmission optical fiber having a signal withdrawn therefrom and injected thereto in its normal state so as to be capable of use in a ring or bus architecture. In the bypass state of the switch, the transmission optical fiber is substantially disengaged so that a signal being transmitted thereby can bypass the switch, and in this state optical fibers connected to a transmitter and a receiver of the bypass switch are maintained in a bent attitude so as to allow signals to be withdrawn and injected thereinto. A loop back path, e.g. a connector optical fiber, is provided which allows a path between the transmitter and the receiver to be completed in the bypass state of the bypass switch, and logic circuitry is provided for analyzing signals detected by the receiver which should have originated from the transmitter for evaluating a state of operation of the transmitter, receiver, and connecting means therefor.

Abstract: A digital phase acquisition circuit includes circuits for detecting an edge of incoming data and a plurality of candidate clock phases, the circuitry further including logic for determining when the data undergoes a predetermined phase transition and at least one candidate phase which undergoes a digitally equivalent transition close in time to the data transition so as to enable the candidate phase to be used for choosing an appropriate clock phase for recovering information representative of the data. The circuit further includes logic for comparing a frequency of the chosen clock pulse and the data and adjusting at least one of these frequencies when a predetermined amount of drift therebetween is detected. The invention allows clock to be recovered within 1 bit time of a predetermined data transition occurring and allows an appropriate clock to be maintained through an entire packet regardless of packet length.

Abstract: A stable high resistant transparent coating is formed by choosing an undoped wide band gap semiconducting oxide, and by forming a film from elements constituting the undoped oxide and from a dopant which is chosen so as to form a doped wide band gap semiconducting oxide, the doped oxide having an electrical resistance greater than the undoped oxide, the electrical resistance of the doped oxide being such that it equals an optimum value when the coating composition is inherently stable.