Abstract: A method and apparatus for making optical fiber preforms using modified chemical vapor deposition (MCVD) A starting tubular member is installed on a chemical vapor deposition apparatus and, using MCVD, a predetermined amount of selectively doped silica is deposited and consolidated on the inner surface to form an intermediate uncollapsed preform tube. At least a portion of the intermediate uncollapsed preform tube is removed from the chemical vapor deposition apparatus, installed in a collapsing apparatus and collapsed. The collapsing uses an oxy-hydrogen burner or a plasma torch. Optionally, additional deposition is performed during the collapsing operation. A stretching may be performed concurrent with the collapsing.

Abstract: A plurality of glass deposition targets are rotated simultaneously and a first plasma torch, having a coil diameter larger than the sum of the target diameters, deposits glass simultaneously on the plurality. After the diameter of the targets reaches a threshold a second plasma torch is used. The diameter of the second plasma torch can provide for simultaneous deposition. In a further embodiment, after the target diameter reaches a second threshold a third plasma torch is used. In a further embodiment the spacing between the axes of rotation of the targets is widened as the target diameter increases. In a still further embodiment a single plasma torch includes movable concentric tubes within its coil to selectively operate as any of a plurality of different diameter plasma torches.

Abstract: A system and a method for providing electrical power to an optical communication system, in particular a telephone system, between a local or central station and a remote station incorporates a conventional fiber optical cable having an electrical conductor or electrically conductive sheath connected to the local station and the remote station already used for transmitting optical signal. A power source is electrically connected to earth ground and to the electrical conductor or sheath at the local station. A power supply is provided at the remote station and electrically connected to the electrical conductor or sheath and to the earth ground thereat. The power supply receives electrical power from the power source located at the local station via the conductor or sheath and the earth ground, the earth ground serving as a return path. The power supply means can thus provide electrical power to an interface device or any other devices provided in the remote station.

Abstract: A composite capillary tube structure made of a plurality of glass layers and methods for making same. This composite includes inner and outer layers of fused silica glass separated by an intermediate layer of a glass material having a higher coefficient of thermal expansion than the fused silica glass. The glass material of the intermediate layer also has a glass transition temperature on the same order as that of fused silica, so that the fused silica layers are maintained under compressive forces over a temperature range of up to about 400.degree. C. Preferably, the intermediate layer is a borosilicate or aluminosilicate glass.

Abstract: An arrangement for an optical fiber pressure sensor is described. This sensor is comprised of two coating layers concentrically clad to and coaxially oriented with an optical fiber. The first coating layer is comprised of a relatively hard optically lossy material which absorbs any light radiating outwardly from the optical fiber. The second coating layer is comprised of a compliant material in which granular particles have been uniformly dispersed. In response to any pressure laterally applied to the sensor, the compliant coating layer imparts micro-bends, onto the optical fiber, which, in turn, couple light from propagating modes to non-propagating modes. As a result, the amplitude (or power) of the light exiting the optical fiber advantageously decreases in response to this pressure.

Abstract: A concentric core optical fiber comprised of an inorganic crystalline, preferably metallic, central core and an optical waveguide having an optical ring core and inner- and outer-glass cladding layers concentrically clad to the central core is described. A long length of such an optical fiber can advantageously support a heavy load for a substantial period of time without fatiguing while providing a transmission medium for optical and/or electrical signals.

Abstract: A magnetically sensitive optical fiber is described. Specifically, this fiber is comprised of a central core containing magnetostrictive material and an optical waveguide, having an optical ring core and inner- and outer-glass cladding layers, clad to the central core. The core is constructed from magnetostrictive material which is readily and inexpensively available as wire of various gauges. The wire is chosen to have a relatively large cross-sectional area with respect to that of the glass cladding layer(s). The resulting optical fiber is advantageously highly sensitive to weak magnetic fields and is also both simple and inexpensive to manufacture.

Abstract: Apparatus for forming a vapor of material to be hydrolyzed and/or oxidized and entraining the vapor in a carrier gas. The source material, in liquid form, is pumped to a point in the column above a porous packing. As the liquid progresses downward through the packing, it encounters a rising countercurrent of carrier gas. The source material vaporizes and is delivered to vapor deposition by the carrier gas. The source material vaporized in the apparatus may alternatively be delivered to an externally heated tubular reactor, or to any other kind of chemical vapor deposition (CVD) reactor.