• 文献标题:   Unintentional Polarization Dependent Pulsewidth of Graphene Mode-Locked Er-Doped Fiber Lasers
  • 文献类型:   Article
  • 作  者:   CHEN TH, LIN YH, CHENG CH, TSAI CT, CHI YC, LIN GR
  • 作者关键词:   garphene, modelocking laser, polarization dependent pulsation
  • 出版物名称:   IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
  • ISSN:   1077-260X EI 1558-4542
  • 通讯作者地址:   Natl Taiwan Univ
  • 被引频次:   2
  • DOI:   10.1109/JSTQE.2016.2564647
  • 出版年:   2017

▎ 摘  要

The unique polarization dependent pulsation phenomenon in a graphene mode-locked erbium-doped fiber laser (ML-EDFL) is explored by the interaction between intracavity weak nonlinear polarization rotation and strong saturable absorption. With unintentional polarization dependent loss (PDL) induced by twisting single-mode fiber (SMF) in an intracavity polarization controller (PC), the unique pulsewidth tunability in a polarizer-free graphene ML-EDFL can be observed. Numerical and experimental procedures are established to combine the hybrid effects and to realize the possible detuning range of intracavity polarization angle for polarization dependent mode-locking dynamics. Twisting SMF induced unintentional PDL in the polarizer-free EDFL contributes a tiny self-amplitude modulation (SAM) coefficient of gamma(NPR) = 5.36 x 10(-4) sin 2 theta(P). The mode-locking stability still relies on the graphene saturable absorption to optimize the SAM up to gamma(total) = 1.46 x 10(-3) and shorten the EDFL pulsewidth to 330 fs. These clearly elucidate the enigma on polarization dependency of most polarizer-free ML-EDFLs with built-in PC. Even an unintentional weak polarization dependency in the EDFL without any polarizer can induce a residual PDL to introduce a polarization angle-dependent SAM coefficient, which declares the importance on controlling intracavity polarization for stabilizing and optimizing the graphene ML-EDFL with unintentional nonlinear polarization rotation induced PDL.