Writing bragg gratings in multicore fibers

Emma Y. Lindley*, Seong Sik Min, Sergio G. Leon-Saval, Nick Cvetojevic, Jon Lawrence, Simon C. Ellis, Joss Bland-Hawthorn

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Fiber Bragg gratings in multicore fibers can be used as compact and robust filters in astronomical and other research and commercial applications. Strong suppression at a single wavelength requires that all cores have matching transmission profiles. These gratings cannot be inscribed using the same method as for single-core fibers because the curved surface of the cladding acts as a lens, focusing the incoming UV laser beam and causing variations in exposure between cores. Therefore we use an additional optical element to ensure that the beam shape does not change while passing through the cross-section of the multicore fiber. This consists of a glass capillary tube which has been polished flat on one side, which is then placed over the section of the fiber to be inscribed. The laser beam enters the fiber through the flat surface of the capillary tube and hence maintains its original dimensions. This paper demonstrates the improvements in core-to-core uniformity for a 7-core fiber using this method. The technique can be generalized to larger multicore fibers.

Original languageEnglish
Article numbere53326
Pages (from-to)1-6
Number of pages6
JournalJournal of Visualized Experiments
Issue number110
Publication statusPublished - 20 Apr 2016
Externally publishedYes


  • engineering
  • issue 110
  • fiber optics
  • fiber Bragg gratings
  • multicore fiber
  • fiber Bragg grating fabrication
  • astrophotonics
  • beam propagation
  • atmospheric suppression


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