Scientific Reports (Dec 2024)

Supercontinuum generation with extended bandwidth and improved purity in graded-index ring-core fiber

  • Qinru Peng,
  • Jian Yang,
  • Yiwen Zhang,
  • Yuanpeng Liu,
  • Yuxi Fang,
  • Wenpu Geng,
  • Zhongqi Pan,
  • Fei Yang,
  • Yang Yue

DOI
https://doi.org/10.1038/s41598-024-80241-4
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 11

Abstract

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Abstract In this paper, we numerically investigate the impact of shape factor (k) on the mode properties of graded-index ring-core fiber (GIRCF). A 50 mol% Ge-doped GIRCF with shape factor of 2 is devised to generate supercontinuum (SC) carrying orbital angular momentum (OAM) modes, which possesses flat dispersion with a minor variation of < ± 30 ps/nm/km from 1090 to 2590 nm. The generated supercontinuum (SC) in the designed GIRCF carrying OAM1,1 mode covers 2305-nm wavelength range from 750 to 3055 nm at − 40 dB level. The graded refractive index profile (RIP), introduced as a new parameter, offers an additional dimension for the design of ring-core fiber (RCF) supporting OAM modes. The graded RIP contributes to the creation of flat and near-zero dispersion in the RCF structures and reduces the spin–orbit coupling (SOC) effect at the material boundary, leading to broader spectral coverage and higher mode purity in the output spectra.