Scientific Reports (May 2017)

The Brillouin gain of vector modes in a few-mode fiber

  • Prabin Pradhan,
  • Dipankar Sengupta,
  • Lixian Wang,
  • Christine Tremblay,
  • Sophie LaRochelle,
  • Bora Ung

DOI
https://doi.org/10.1038/s41598-017-01621-7
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 7

Abstract

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Abstract In this work, we demonstrate the measurement of the Brillouin gain spectra of vector modes in a few-mode fiber for the first time using a simple heterodyne detection technique. A tunable long period fiber grating is used to selectively excite the vector modes supported by the few-mode fiber. Further, we demonstrate the non-destructive measurement of the absolute effective refractive indices (n eff ) of vector modes with ~10−4 accuracy based on the acquired Brillouin frequency shifts of the modes. The proposed technique represents a new tool for probing and controlling vector modes as well as modes carrying orbital angular momentum in optical fibers with potential applications in advanced optical communications and multi-parameter fiber-optic sensing.