Abstract: A new class of nanostructured RE-doped SiO2-base materials that display superior fluorescence properties is provided. In particular, high gain combined with a broad and flat spectral band width is observed in material composed of a high fraction of a nano-dispersed metastable silicate phase in a glassy SiO2 matrix, produced by partial devitrification (crystallization) of several glassy Al2O3/Er2O3- and Y2O3/Er2O3-doped SiO2 compositions. Also, a highly deconvoluted spectral emission, with several prominent peaks, is observed in completely devitrified material, consisting of a uniform nano-dispersion of an equilibrium silicate phase in a crystobalite SiO2 matrix. Such enhanced fluorescence properties were observed in heat treated nanopowders prepared by vapor-phase, solgel, rapid solidification, and spray-pyrolysis methods.

Abstract: A preform for a low loss fiber optic cable and method and apparatus for fabricating such a preform is provided. The method includes providing AlCl3 and CVD precursors and locally doping CaCl3. Alkali and/or alkaline earth fluxing agents can be introduced. The alkali and/or alkaline earths are doped along with the aluminum into the silica glass core.

Abstract: A preform for a low loss fiber optic cable and method and apparatus for fabricating such a preform is provided. The method includes providing AlCl3 and CVD precursors and locally doping CaCl3. Alkali and/or alkaline earth fluxing agents can be introduced. The alkali and/or alkaline earths are doped along with the aluminum into the silica glass core.

Abstract: A preform for a low loss fiber optic cable and method and apparatus for fabricating such a preform is provided. The method includes providing AlCl3 and CVD precursors and locally doping CaCl3. Alkali and/or alkaline earth fluxing agents can be introduced. The alkali and/or alkaline earths are doped along with the aluminum into the silica glass core.

Abstract: A method and apparatus for testing and remediating the effects of radon infiltration in buildings. The method of this invention places fiber glass materials over radon-emitting surfaces in order to entrap radon and radon progeny. The fiber glass materials can be formed into mats having a packed geometry. Each mat has fiber bundles having several thousand individual fibers. Each fiber has an approximate diameter size of about 50 microns. The glass fiber consists of a silicon oxide glass that may be doped, for example, with trivalent cerium ions. The mats can be of any geometrical configuration, such as rectangular.

Abstract: A three-axis fiber optic vector magnetometer is provided for measuring both he direction and magnitude of a DC or low frequency magnetic field. The magnetometer includes an optical interferometer system including a sensing fiber arm disposed with three respective sensing portions perpendicular to one another and attached to a uni-directional sensor material. The interferometer system also includes a reference fiber arm and a laser light source for generating and introducing a laser light into both of the arms. Respective biasing devices generate a reference AC magnetic bias and a respective reference frequency in the three sensing portions. A detecting device detects a reference light signal from the reference fiber arm and the magnetically altered sensing light signal from the sensing fiber arm and forms an interferometer output signal.

Abstract: A device and method for interconnecting multiterminal electronic devices. e device and method combine the use of input light sources, output light detectors and an optical waveguide matrix device for routing the signals from various preselected input terminals to various other output terminals. The optical waveguide matrix device includes a number of intersecting optical waveguides formed on a base. The intersecting waveguides are optically coupled by means of reflecting surfaces formed at the nodes of intersection.

Abstract: A fiber optic magnetometer for detecting DC magnetic fields includes a first optical fiber having a magnetostrictive jacket thereon which defines a sensing arm, and a second fiber defining a reference arm. A first AC magnetic field of frequency .omega..sub.o and a second AC field of frequency .omega..sub.s are imposed on the magnetostrictive jacket so as to cause a time varying optical path length change, having .omega..sub.o, (.omega..sub.o +.omega..sub.s), and (.omega..sub.o -.omega..sub.s) components in the sensing arm fiber. This induces a corresponding time varying phase shift, also having the above components, in light transmitted through the sensing arm fiber which is detected by a phase detector. The phase detector produces a signal proportional to the phase shift, this signal being passed to a lock-in amplifier set to amplify at .omega..sub.o. .omega..sub.s is sufficiently small such that the lock-in amplifier filters all components other than the .omega..sub.o, (.omega..sub.o +.omega..sub.s), and (.

Abstract: A fiber optic magnetometer for detecting DC magnetic fields includes a first optical fiber having a magnetostrictive jacket thereon which defines a sensing arm, and a second fiber defining a reference arm. An AC magnetic field of frequency .omega..sub.o and constant amplitude is imposed on the magnetostrictive jacket so as to cause a time varying optical path length change, having an .omega..sub.o component, in the sensing arm fiber. This induces a corresponding time varying phase shift, also having an .omega..sub.o component, in light transmitted through the sensing arm fiber which is detected by a phase detector. The phase detector produces a signal proportional to the phase shift, this signal being passed to a lock-in amplifier set to amplify at .omega..sub.o. The lock-in amplifier produces an output signal proportional to the amplitude of the .omega..sub.o component, wherein this amplitude is proportional to any DC magnetic fields to which the device is exposed.

Abstract: A fiber optic magnetic gradiometer for measuring both ac and dc magnetic field gradients. The gradiometer utilizes an optical interferometer with magnetostrictive magnetic field sensing elements in each of the interferometer arms. Ac and dc magnetic field biasing is achieved by disposing each of the magnetic field sensing elements within its own magnetic field coil and utilizing a variable dc current source for applying dc current to each magnetic coil. An ac current source at frequency w.sub.o connected across the circuits for the dc current sources is used in conjunction with a variable attenuator to control the ac bias to the respective magnetic coils. The detected output from the interferometer is processed either by bandpass filters or a spectrum analyzer to obtain the signal component at w.sub.o, which is proportional to the external dc gradient magnetic field, and at w.sub.o +w.sub.s, (where w.sub.

Abstract: A sensing element of magnetostrictive material associated with an optical fiber of an interferometer arm defining apparatus for detecting magnetic fields. The magnetostrictive material is adhered in close co-extensive adjacency with the optical fiber and in the presence of a magnetic field undergoes responsive longitudinal dimension changes which strains the optical fiber and induces a strain related phase shift in an optically propagating beam in the fiber detectable by interferometry.

Abstract: Optical fibers of silica and plastic composition are rendered relatively stable to nuclear radiation induced optical losses by preirradiating with a high initial radiation dosage. Subsequent exposure of the radiation hardended fibers produce substantially lower radiation induced optical loss and faster fiber transmission recovery rates.

Abstract: A new method for preparing low loss multimode and monomode glass optical fibers which avoids casting or pouring the core and clad melts is disclosed. The new technique is based on a reactive-gas-transport approach which avoids contamination from absorbing impurities and scattering centers by reacting the glass melt with reactive gases which remove impurities and increase the refractive index of the fiber.