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: 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 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: An optical fiber distribution network includes non-destructive read taps disposed in series which create extremely small attenuations of an optical signal being tapped, and which increase the bandwidth of an optical fiber being tapped. The network further includes non-destructive write taps disposed in another series which each inject an optical signal into a second optical fiber while inducing minimal attenuation of a preexisting optical signal in the second fiber.

Abstract: A mode filter for reducing a dynamic range of a write optical fiber bus which utilizes taps which initially inject optical signals into an optical fiber which have intensities skewed towards higher order modes rather than lower order modes as compared to equilibrium for the fiber functions to preferentially attenuate outermost modes rather than lowermost modes in the fiber so as to reduce a required dynamic range for an optical receiver.

Abstract: A distribution optical fiber network includes a light source having a mode volume less than a distribution optical fiber, the light source being connected to the fiber so as to minimize the number and order of modes initially supported by the fiber by aligning an optical center of the light source with a geometric center of the fiber.

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 optical fiber distribution network includes non-destructive read taps disposed in series which create extremely small attenuations of an optical signal being tapped, and which increase the bandwidth of an optical fiber being tapped. The network further includes non-destructive write taps disposed in another series which each inject an optical signal into a second optical fiber while inducing minimal attenuation of a pre-existing optical signal in the second fiber.

Abstract: A method of determining splice loss 10 log (1-P.sub.R /P.sub.O) that is practiced at the location of a splice between one ends of input and output fibers. A reference level P.sub.O of light that is transmitted out of the one end of the input fiber is obtained by inserting it into an integrating cylinder of split block construction, prior to making the splice, and coupling diffuse light in the cylinder to a radiometer. After the ends of the fibers are spliced together, the splice and a significant portion of the adjacent length of output fiber exhibiting substantial leaky mode radiation that is caused by the splice, is located in the cylinder. With light of the reference level in the input fiber being incident on the splice, the radiometer provides an indication P.sub.R of light lost as a result of the splice. The indication P.sub.

Abstract: A small amount of light that is transmitted in one of a pair of optical fibers having cleaved ends thereof loosely brought into butt contact is converted to leaky modes in the other fiber. Leaky mode light that is radiated out of the perimeter of the other fiber is collected in an integrating enclosure located proximate its one end and extending over a limited length of the other fiber. The light in the enclosure is detected for producing a measure of the degree of alignment of the adjacent ends of the fibers. After the cleaved ends of the fibers are aligned with micromanipulators so as to null the intensity of detected leaky mode radiation, an electrical arc is created across them for permanently joining the fiber ends together in a splice. The integrity of the resultant splice is determined by producing a measure of the splice loss 10 log (1-P.sub.R /P.sub.O), where P.sub.

Abstract: Apparatus for field measurement of the insertion loss of a splice between one ends of first and second optical fibers comprises an integrating sphere that is split along its axis and which has a fiber input port, a pair of spaced-apart padded holes on the axis for receiving associated fibers so as to center the splice inside the sphere, and an output port receiving one end of a fiber bundle which couples diffuse light in the sphere to a radiometer. A baffle plate in the sphere prevents light rays from the splice being incident on the output port. The splice loss is determined by inserting the one end of the first fiber into the input port, with the other end illuminated by light from a source, and reading a reference level of light coupled to the radiometer. The two fibers are then spliced together and the splice located inside the sphere.

Abstract: The dispersion of optical signals derived from a spontaneous emitter when coupled into an optical fiber waveguide is substantially reduced by optically coupling a narrow band pass interference filter between the emitter and waveguide. Only a narrow portion of the broad spectral width emission of the emitter is thereby coupled into the waveguide to provide emitter modulation rates limited only by the rise-time of the emitter. In the preferred embodiment, the coupled spectral portion corresponds to the wavelengths of peak emission. Additionally, the filter is a thin film filter deposited onto either the light-exiting face of the emitter or onto the light-receiving end of the fiber waveguide.

Abstract: A fiber coupled light emitting diode module is provided which may be utilized for plug-in incorporation into a fiber optical communications system and for easy connection to a driving voltage source. Means are included in the module for facilitating manufacture since the location of the light emitting diode is not critical within the device and the device may be operated efficiently since the heat which is generated at the light emitting diode is conducted away to the exterior of the module for dissipation.