Large flattened mode optical fiber with raised index ring around the outer edge of the fiber core has been fabricated through modified chemical vapour deposition process to raise the threshold for non-linear interaction in high power laser fiber. The conversion of the fundamental mode shape from a Bessel function to a top hat function, enhances the effective area of the core intersected by the mode without increasing the physical size of the core. The shape of the fundamental mode is observed to be strongly dependent on the width of the raised index ring from the modal analysis. Suitable fiber parameters have also been estimated through the modal field analysis. Fabrication process steps have been optimized to achieve the desired fiber parameters. Modal field distribution, transmission properties and bending loss of the fabricated fibers have been characterized.

Date Published: 23 August 2011
PDF: 6 pages
Proc. SPIE 8173, Photonics 2010: Tenth International Conference on Fiber Optics and Photonics, 81730B (23 August 2011); doi: 10.1117/12.898797

Published in SPIE Proceedings Vol. 8173:
Photonics 2010: Tenth International Conference on Fiber Optics and Photonics
Sunil K. Khijwania; Banshi D. Gupta; Bishnu P. Pal; Anurag Sharma, Editor(s)