Abstract: A self-correcting protective circuit for providing a reference voltage to a backplane bus wherein the circuit includes a primary transistor, current sensing resistor and diode connected between a supply voltage and the backplane. The combination of a current-limiting resistor and a control transistor is used to sense current flow to the board through the primary transistor and limit same when the backplane bus voltage fluctuates.

Abstract: An output of a light source coupled to an optical fiber is controlled by an apparatus comprising a mode stripper for stripping a first part of the optical signal from the cladding of the optical fiber, means for bending the optical fiber and withdrawing a second part of the optical signal from a core of the fiber downstream from the stripper, means for detecting the second part of the optical signal, and feedback means for using the detected second signal part to control an output of the light source to better linearize an amount of power injected into the fiber.

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 A light reflector extending transverse to the plane deflects the withdrawn light towards the end surface of a light element disposed completely outside the plane.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 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 A light reflector extending transverse to the plane deflects the withdrawn light towards the end surface of a light element disposed completely outside the plane.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 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: 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 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.