Abstract: The invention relates to a mode filter for reducing higher-order modes, with an optical fiber (1), which has a core (2) and a cladding (3) surrounding the latter, wherein the cladding (3) and core (2) have refractive indices that differ from one another. In order to develop an alternative to the prior art, the mode filter according to the invention is designed in such a manner that the fiber (1) has, in a transition region (4) between core (2) and cladding (3), at least one local refractive index modification region (5) which is arranged in the radially outer region of the core (2) and extends into the region of the cladding (3).
Type:
Grant
Filed:
September 27, 2012
Date of Patent:
June 7, 2016
Assignees:
Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e. V., Fried-Schiller-Universitaet Jena
Inventors:
Christian Voigtlaender, Jens Ulrich Thomas, Robert Williams, Stefan Nolte, Andreas Tuennermann