Communications Engineering (Jan 2024)

Frequency-dependent impairment calibration and estimation for a 96 GBaud coherent optical transceiver

  • Longquan Dai,
  • Ziheng Zhang,
  • Zicai Cao,
  • Shuchang Yao,
  • Tianming Li,
  • Yudi Fu,
  • Jing Dai,
  • Yaqin Wang,
  • Ming Luo,
  • Xi Xiao,
  • Mengfan Cheng,
  • Qi Yang,
  • Ming Tang,
  • Deming Liu,
  • Lei Deng

DOI
https://doi.org/10.1038/s44172-023-00147-3
Journal volume & issue
Vol. 3, no. 1
pp. 1 – 10

Abstract

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Abstract For 800 Gbps/λ and beyond optical transmission systems, frequency-dependent impairments (FDI) degrade coherent optical transceiver (CO-TRx) performance severely. Calibration and compensation of such FDI in factories includes amplitude/phase frequency response (AFR/PFR), skew, and ripple for both transmitters(Tx) and receivers (Rx). However, due to the polarization rotation and phase rotation effects in optical link, the separation and extraction of FDI from different polarization or I/Q tributaries is challenging. Here we report a FDI calibration method based on orthogonal separation scheme and frequency domain analysis. The proposal can simultaneously characterize and separate the Tx/Rx sides FDI including AFR, PFR, and time skew of four tributaries. Finally, the effectiveness is demonstrated by transmitting a 96 GBuad Nyquist-16QAM signal on a 64 GBaud-class CO-TRx.