J-plasma Gmbh

Leoni Kabel Gmbh

J-fiber Gmbh

Jörg Kötzing

Lothar Brehm

Robert Hanf

Wolfgang Hämmerle

Matthias Auth

Ralitsa Rosenow

Roland Heinze

Hans Engler

The invention relates to a method for producing a glass-fibre preform with a core of a polygonal cross section by using a rod-in-tube method and comprising the method steps of: providing a core rod () of a polygonal core rod cross section (), producing a sectored sandwich tube () from a starting tube (), wherein the lateral surface of the starting tube () is slit in the longitudinal direction into a series of outer segments (), and so the tube cross section of the starting tube () is subdivided into a series of sectors of a circle (), inserting the core rod () into the sectored sandwich tube () and aligning it and, in the case of one embodiment, inserting the core rod () and the sectored sandwich tube () into an outer casing tube () with a complete annular cross section and melting the sectored sandwich tube () and possibly the outer casing tube () onto the sectored sandwich tube (), wherein the outer segments () of the sectored sandwich tube () are fused to the respective side surfaces () of the core rod ().

Method for producing a glass-fibre preform with a core of a polygonal core cross section

Preform for an optical waveguide containing a core with a non-circular geometry and at least one cladding layer, in which the dopand concentration of the cladding layer is increased compared to the dopand concentration of a preform with circular core geometry and identical NA. A method for the production of a preform for an optical fiber is provided. An optical waveguide with a nominal dopand concentration of c(eff)&#xd7;F&#x2264;c(nom) in at least one cladding layer is also provided.

Preform for an optical waveguide and a fiber with non-circular core

The invention describes a method for the removal of glass where the parameters of the removal process are set over the length of the substrate (preform) so that a uniform removal can be achieved over the complete substrate length.

Method for the unidirectional and or bidirectional removal of a cladding layer of an optical preform

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.

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Jena, Germany

Jörg Kötzing