Utilizing adaptive optics to mitigate intra-modal-group power coupling of graded-index few-mode fiber in a 200-Gbit/s mode-division-multiplexed link

Runzhou Zhang*, Hao Song, Haoqian Song, Zhe Zhao, Giovanni Milione, Kai Pang, Jing Du, Long Li, Kaiheng Zou, Huibin Zhou, Cong Liu, Karapet Manukyan, Nanzhe Hu, Ahmed Almaiman, Jeffery Stone, Ming Jun Li, Brittany Lynn, Robert W. Boyd, Moshe Tur, Alan E. Willner

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

We experimentally demonstrate the utilization of adaptive optics (AO) to mitigate intra-group power coupling among linearly polarized (LP) modes in a graded-index few-mode fiber (GI FMF). Generally, in this fiber, the coupling between degenerate modes inside a modal group tends to be stronger than between modes belonging to different groups. In our approach, the coupling inside the LP11 group can be represented by a combination of orbitalangular-momentum (OAM) modes, such that reducing power coupling in OAM set tends to indicate the capability to reduce the coupling inside the LP11 group. We employ two output OAM modes l DC1 and l D..1 as resultant linear combinations of degenerate LP11a and LP11b modes inside the LP11 group of a ∼0.6-km GI FMF. The power coupling is mitigated by shaping the amplitude and phase of the distorted OAM modes. Each OAM mode carries an independent 20-, 40-, or 100-Gbit/s quadrature-phaseshift-keying data stream. We measure the transmission matrix (TM) in the OAM basis within LP11 group, which is a subset of the full LP TM of the FMF-based system. An inverse TM is subsequently implemented before the receiver by a spatial light modulator to mitigate the intramodal-group power coupling. With AO mitigation, the experimental results for l =+1 and l =-1 modes show, respectively, that (i) intra-modal-group crosstalk is reduced by >5.8 dB and >5.6 dB and (ii) near-error-free bit-errorrate performance is achieved with a penalty of ∼0.6 dB and ∼3.8 dB, respectively.

Original languageEnglish
Pages (from-to)3577-3580
Number of pages4
JournalOptics Letters
Volume45
Issue number13
DOIs
StatePublished - 1 Jul 2020

Fingerprint

Dive into the research topics of 'Utilizing adaptive optics to mitigate intra-modal-group power coupling of graded-index few-mode fiber in a 200-Gbit/s mode-division-multiplexed link'. Together they form a unique fingerprint.

Cite this