Femtosecond point-by-point inscription of 3D FBG arrays in 7-core fibers with straight and twisted cores

Alexey Wolf, Kirill Bronnikov, Sergey Yakushin, Alexandr Dostovalov, Sergey Zhuravlev, Mikhail Salganskii, Olga Egorova, Sergey Semjonov, Sergey Babin

Research output: Chapter in Book/Report/Conference proceedingConference contributionResearchpeer-review


We present the results on fabrication of 3D fiber Bragg grating (FBG) arrays in specialty 7-core optical fibers with straight or twisted (spun) cores. Femtosecond laser inscription technology allowed us to modify the fibers through the acrylate or polyimide protective coatings that significantly increases the durability of the FBG sensors as compared to conventional UV inscription approach, requiring the coating removal. Custom-made 7-core fiber with polyimide coating opens up new prospects for shape sensors operating in high-Temperature environment. Twisted-core fiber makes it possible to measure not only the shape, but also the direction of fiber torsion that is essential for a free-standing sensors. A novel method enabling core-selective FBGs inscription in a 7-core spun optical fiber is presented in this work. By using the created sensors bending radii down to several millimeters can be measured with a high precision. Separation of different core FBGs by wavelength makes it possible to combine several cores during their interrogation, which allows for sensor measurements through a single optical port.

Original languageEnglish
Title of host publicationSeventh European Workshop on Optical Fibre Sensors
EditorsKyriacos Kalli, Gilberto Brambilla, Sinead O'Keeffe
Number of pages6
ISBN (Electronic)9781510631236
Publication statusPublished - 1 Jan 2019
Event7th European Workshop on Optical Fibre Sensors, EWOFS 2019 - Limassol, Cyprus
Duration: 1 Oct 20194 Oct 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


Conference7th European Workshop on Optical Fibre Sensors, EWOFS 2019


  • multicore fiber
  • fiber Bragg grating
  • optical fiber sensor
  • femtosecond laser micromachining


Dive into the research topics of 'Femtosecond point-by-point inscription of 3D FBG arrays in 7-core fibers with straight and twisted cores'. Together they form a unique fingerprint.

Cite this