Modal field deformation and transition losses in UV side-written optical fibers.
The asymmetry of the UV-induced refractive-index profile in photosensitive optical fibers causes a deformation of the modal fields, resulting in transition losses between UV-exposed and unexposed fiber sections up to 0.1 dB for UV-induced index changes of the order of <or=10(-2). A numerical analysis of the transition losses is developed. It is verified experimentally that the loss is caused by coupling of power of the fundamental mode to cladding modes at such a transition.
Renner
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H
Arbeitsbereich Optik und Messtechnik, Technische Universität Hamburg-Harburg, Eissendorfer Strasse 40, 21073 Hamburg, Germany. renner@tu-harburg.de
Johlen
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D
Brinkmeyer
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E