Disclosed in the present invention is a beam coherence eliminating element. The optical medium material of the element comprises microcrystalline glass, wherein microcrystalline particles therein have a size of 0.1-1000 nm and are distributed randomly. As the crystals in the microcrystalline glass can change the phase of light beams, the microcrystalline glass can change the phase of the light beams randomly, thereby eliminating the coherence of the beams. The crystal size of the microcrystalline glass is small, and thus does not affect the transmission efficiency of light beams. The element of the present invention has a simple structure and is convenient to use, and can be added in the process of beam transmission to easily eliminate beam coherence.

Glass compositions and glass fibers having low dielectric constants and low dissipation factors that may be suitable for use in electronic applications and articles are disclosed. The glass fibers and compositions of the present invention may include between 48.0 to 58.0 weight percent SiO.sub.2; between 15.0 and 26.0 weight percent B.sub.2O.sub.3; between 12.0 and 18.0 weight percent Al.sub.2O.sub.3; between greater than 0.25 and 3.0 weight percent P.sub.2O.sub.5; between greater than 0.25 and 7.00 weight percent CaO; 5.0 or less weight percent MgO; between greater than 0 and 1.5 weight percent SnO.sub.2; and 6.0 or less weight percent TiO.sub.2. Further, the glass composition has a glass viscosity of 1000 poise at a temperature greater than 1350 degrees Celsius and a liquidus temperature greater than 1000 degrees Celsius.

Apparatus and methods for forming melt-formed fibres and melt-formed biosoluble fibers are disclosed. The apparatus comprises a spinning head comprising one or more rotors; a plurality of nozzles or slots disposed around at least part of the one or more rotors; a conveyor; and a barrier between the spinning head and the conveyor.

An optical element is provided. The optical element may comprise a material, the material being a matrix and a set of particles included in the matrix, the material having a molar fraction of SiO.sub.2 higher than or equal to 65 percent, each particle having a dimension smaller than or equal to 80 nanometers.

An inorganic fiber containing a fiberization product of a compound comprising at least one alkaline earth silicate, at least one compound containing an element from group VII and/or IX of the periodic table, and optionally alumina and/or boria. The inclusion of a suitable amount of at least one compound containing an element from group VII and/or IX of the periodic table of elements to an alkaline-earth silicate inorganic fiber reduces fiber shrinkage, decreases biopersistence in physiological solutions, and enhances mechanical strength beyond that of alkaline earth silicate fibers without the presence of the at least one compound containing an element from group VII and/or IX. Also provided are methods of preparing the inorganic fiber and of thermally insulating articles using thermal insulation prepared from the inorganic fibers.

Disclosed is a method of making high temperature fiber including incorporating an inorganic atom into a polymer precursor fiber to form a modified polymer precursor fiber and converting the modified polymer precursor fiber to a high temperature fiber having a bonded inorganic atom.

Disclosed in the present invention is a beam coherence eliminating element. The optical medium material of the element comprises microcrystalline glass, wherein microcrystalline particles therein have a size of 0.1-1000 nm and are distributed randomly. As the crystals in the microcrystalline glass can change the phase of light beams, the microcrystalline glass can change the phase of the light beams randomly, thereby eliminating the coherence of the beams. The crystal size of the microcrystalline glass is small, and thus does not affect the transmission efficiency of light beams. The element of the present invention has a simple structure and is convenient to use, and can be added in the process of beam transmission to easily eliminate beam coherence

Glass compositions and glass fibers having low dielectric constants and low dissipation factors that may be suitable for use in electronic applications and articles are disclosed. The glass fibers and compositions of the present invention may include between 48.0 to 58.0 weight percent SiO.sub.2; between 15.0 and 26.0 weight percent B.sub.2O.sub.3; between 12.0 and 18.0 weight percent Al.sub.2O.sub.3; between greater than 0.25 and 3.0 weight percent P.sub.2O.sub.5; between greater than 0.25 and 7.00 weight percent CaO; 5.0 or less weight percent MgO; between greater than 0 and 1.5 weight percent SnO.sub.2; and 6.0 or less weight percent TiO.sub.2. Further, the glass composition has a glass viscosity of 1000 poise at a temperature greater than 1350 degrees Celsius and a liquidus temperature greater than 1000 degrees Celsius.

An optical element is provided. The optical element may comprise a material, the material being a matrix and a set of particles included in the matrix, the material having a molar fraction of SiO.sub.2 higher than or equal to 65 percent, each particle having a dimension smaller than or equal to 80 nanometers.

An inorganic fiber containing a fiberization product of a compound comprising at least one alkaline earth silicate, at least one compound containing an element from group VII and/or IX of the periodic table, and optionally alumina and/or boria. The inclusion of a suitable amount of at least one compound containing an element from group VII and/or IX of the periodic table of elements to an alkaline-earth silicate inorganic fiber reduces fiber shrinkage, decreases biopersistence in physiological solutions, and enhances mechanical strength beyond that of alkaline earth silicate fibers without the presence of the at least one compound containing an element from group VII and/or IX. Also provided are methods of preparing the inorganic fiber and of thermally insulating articles using thermal insulation prepared from the inorganic fibers.