Abstract: A fire resistant composite material comprising: a matrix comprising one or more liquid and one or more of silicates of the elements of Groups 1, 2, 13 and/or 14 of the periodic table, phosphates of the elements of Group 13 of the periodic table and/or organo compounds of the elements of Group 13 of the periodic table; and a cooling agent comprising one or more of MOH, M2O, M2 SO4, MHSO4, M(PO3)3, MxH3-xPO4 (where x=0 to 3), M2CO3, MHCO3, borates such as M2 [B4O5(OH)4](where M=Li, Na, K, and/or NH4), M?(OH)2, M?O, M?CO3, M?SO4, M?PO4(where M?=Ca, Mg, Ba, Sr, and/or Fe), Al(OH)3, Fe(OH)3, Si(OH)4, SiO(OH)2, FeO(OH), AlO(OH), salts thereof, silica gel, molecular sieves, glycols, polyols, non-flammable organic solvents, dried alkali metal silicates and/or saccharides; and/or an isolating agent comprising one or more of hollow microspheres,foam microspheres, glass flakes, ceramic flakes, wood chips and/or cellulose chips.

Abstract: Methods for producing a semifinished part for the manufacture of an optical fiber are disclosed. The methods are optimized in terms of bending. The methods include the steps of providing a shell tube with a shell refractive index which is lower in relation to the light-conducting core. Then, at least one protective, intermediate and/or barrier layer is applied to a radially outermost and/or innermost tube surface of the respective shell tube, wherein a build-up of light-conducting layers is realized on the inner side and/or the outer side of the shell tube. Finally, the shell tubes are joined by collapsing so as to form the semifinished part.

Abstract: Methods for producing a semifinished part for the manufacture of an optical fiber are disclosed. The methods are optimized in terms of bending. The methods include the steps of providing a shell tube with a shell refractive index which is lower in relation to the light-conducting core. Then, at least one protective, intermediate and/or barrier layer is applied to a radially outermost and/or innermost tube surface of the respective shell tube, wherein a build-up of light-conducting layers is realized on the inner side and/or the outer side of the shell tube. Finally, the shell tubes are joined by collapsing so as to form the semifinished part.

Abstract: The invention relates to an optical fiber, in particular a laser fiber, containing a doped glass fiber core (1) and cladding (2) around the latter with a refraction index profile which decreases outwards from the fiber core. The optical fiber is distinguished by at least one intermediate layer (3, 4, 5) being disposed between the glass fiber core and the cladding to reduce the mechanical tension therebetween. In one advantageous embodiment, the intermediate layer is doped in such a way as to ensure a stepped mechanical tension distribution between the glass fiber core and the cladding, and is co-doped in such a way as to reduce the refractive index and counteract the refraction index-increasing effect of the intermediate layer doping.

Abstract: A method for producing a glass fiber, through longitudinally drawing a preform in a drawing kiln, wherein cooling the glass fiber is performed in at least three time periods, wherein the glass fiber is exposed to a first time based cooling rate above a crystallization temperature range, to a second time based cooling rate that is greater than the first time based cooling rate within the crystallization temperature range, and to a third time based cooling rate which is smaller than the second time based cooling rate below the crystallization temperature range.

Abstract: An optical fiber has a core region, a cladding region and at least one spacer layer disposed between the core region and the cladding region. The core region is positively doped and has a positive refractive index with respect to the glass matrix of the optical fiber. The cladding region is negatively doped and has a refractive index of at most zero with respect to the glass matrix. The numerical aperture of the optical fiber is composed of variable proportions of the positively doped core region and the negatively doped cladding region and results from the refractive indices of both regions.

Abstract: The invention relates to an optical waveguide and a semifinished product for producing an optical waveguide having optimized diffraction properties, comprising a trench structure that has a radius-dependent graded refractive index curve and/or a concentric depressed refractive index profile within a core zone (2) and/or within a cladding zone (4). In one embodiment of the optical waveguide and semifinished product, the structure is formed from a succession of differently doped regions containing dopants that are introduced into a base matrix and lower and/or increase the refractive index.

Abstract: The invention relates to an optical fiber, in particular a laser fiber, containing a doped glass fiber core (1) and cladding (2) around the latter with a refraction index profile which decreases outwards from the fiber core. The optical fiber is distinguished by at least one intermediate layer (3, 4, 5) being disposed between the glass fiber core and the cladding to reduce the mechanical tension therebetween. In one advantageous embodiment, the intermediate layer is doped in such a way as to ensure a stepped mechanical tension distribution between the glass fiber core and the cladding, and is co-doped in such a way as to reduce the refractive index and counteract the refraction index-increasing effect of the intermediate layer doping.

Abstract: A method for producing a glass fiber, through longitudinally drawing a preform in a drawing kiln, wherein cooling the glass fiber is performed in at least three time periods, wherein the glass fiber is exposed to a first time based cooling rate above a crystallization temperature range, to a second time based cooling rate that is greater than the first time based cooling rate within the crystallization temperature range, and to a third time based cooling rate which is smaller than the second time based cooling rate below the crystallization temperature range.

Abstract: The invention relates to a multi-nozzle, tubular plasma deposition burner (1) for producing preforms as semi-finished products for optical fibers, wherein a media stream containing glass starting material and a carrier gas is fed to the burner (1), means for feeding at least one dopant using at least one precursor gas and a substantially perpendicular orientation of the burner gas longitudinal axis relative to the center axis of the substrate (4). According to the invention, a first partial stream of a first gas or gas mixture, in particular a precursor gas, is fed to the plasma and to the substrate (4) by way of at least one nozzle running in the burner longitudinal axis and a second partial stream of the first gas or of another gas or gas mixture, in particular a precursor gas, is fed to the plasma and the substrate by way of another nozzle (5); said gases or gas mixtures are fed in such a way that said partial streams combine in the vicinity of the substrate.