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. The invention further relates to an application of at least one doped barrier layer to a core region during preparation of the preform to avoid diffusion of special core dopants from the core during the collapse process, and to allow the diffusion of special dopants between the barrier layer and the core layer.
Abstract:
For collection of dust from gases at temperatures up to 900.degree. C. and under presssures up to 20 bars by means of gas-permeable two-dimensional filter elements, an apparatus is proposed which comprises a pressure-resisting cylindrical outer housing, which contains a gas-tight pear-shaped inner housing, which is movably mounted in the outer housing by a means of a heat-insulating carrying structure and is provided with a tubular gas-outlet port and comprises a cambered bottom, which contains cylindrical filter elements. A pressure-confining gas-tight compensator is provided between the tubular gas-outlet port of the inner housing and the outer housing. Because the "pressure-confining" and "supporting" functions are separate, the internal components, which will be subjected to temperatures up to 900.degree. C., can be joined to the pressure-confining wall of the outer housing, which must not be heated above 200.degree. C.
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 reactor for the production of C2 to C8 olefins from gaseous oxygenate and H2O and one or more material flows containing C2 C4, C5, C6, C7, C8 olefin and paraffin at 400° to 470° C., wherein several reaction stages which the material flow can pass through from the top to the bottom, each consisting of a support base with a catalyst layer situated on it, are arranged in a closed, upright container. In order to be able in each case to lower the temperature of the reaction mixture leaving the reaction stages before it enters into the next reaction stage, it is provided that each support base consists of cells which are placed closely next to each other with no gaps and which are securely attached to each other and filled with catalyst, and in the space formed by two neighboring reaction stages, respectively, an assembly of nozzle tubes is installed for spraying a liquid phase containing H2O and DME and/or MeOH, using a water-saturated gas phase containing mainly DME and/or MeOH, in the direction of the following reaction stage downstream.
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:
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:
A burner for the partial oxidation of liquid, carbonaceous fuel with steam and an oxygen-containing gas a well as the process in which this burner is used, wherein the parts of the outlet orifice of the burner directed towards the combustion chamber are wholly or partly provided with a coating or with a diffusion layer for protection against thermal load and/or corrosion.
Abstract:
A reactor is described for the production of C2 to C8 olefins from gaseous oxygenate and H2O and one or more material flows containing C2 C4, C5, C6, C7, C8 olefin and paraffin at 400° to 470° C., wherein several reaction stages which the material flow can pass through from the top to the bottom, each consisting of a support base with a catalyst layer situated on it, are arranged in a closed, upright container. In order to be able in each case to lower the temperature of the reaction mixture leaving the reaction stages before it enters into the next reaction stage, it is provided that each support base consists of cells which are placed closely next to each other with no gaps and which are securely attached to each other and filled with catalyst, and in the space formed by two neighboring reaction stages, respectively, an assembly of nozzle tubes is installed for spraying a liquid phase containing H2O and DME and/or MEOH, using a water-saturated gas phase containing mainly DME and/or MEOH, in the direction of the following reaction stage downstream.
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.