Frontiers in Physics (Jun 2020)

Orbital Angular Momentum Optical Amplifier Based on PbS-Doped Ring-Core Fiber

  • Lingmin Xu,
  • Yana Shang,
  • Jinhong Yang,
  • Zhenyi Chen,
  • Fufei Pang,
  • Huanhuan Liu,
  • Yanhua Dong,
  • Na Chen,
  • Jianxiang Wen,
  • Tingyun Wang

DOI
https://doi.org/10.3389/fphy.2020.00198
Journal volume & issue
Vol. 8

Abstract

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A unique orbital angular momentum (OAM) optical amplifier based on a ring-core fiber doped with lead sulfide (PbS) is realized for the first time in this study. The PbS-doped ring-core fiber is fabricated using the modified chemical vapor deposition method. The cross-sectional microscope image of the fiber is obtained. The difference in the refractive index between the ring core and the fiber cladding measured by a three-dimensional refractive index tester reaches 1%. The sulfur and lead content in the ring-core of the PbS-doped ring-core fiber is confirmed by energy spectrum analysis. A first-order OAM optical amplifier is built based on the PbS-doped ring-core fiber. The experiment confirms that the air-hole PbS-doped ring-core fiber can support the OAM |l| = 1 modes. In addition, 2.3 dB of on–off gain is obtained for the OAM |l| = 1 modes at 1,550 nm. The fluorescence spectrum obtained using the backward pumping method ranges from 1,100 to 1,600 nm.

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