Abstract The Kramers–Kronig (KK) receiver has been used for dispersion compensation in direct detection systems employing external-modulator-based transmitters. In this paper, we investigate the use of the KK receiver for dispersion compensation in a direct detection system based on a directly-modulated laser. We show the validity of the KK receiver by considering a linear contribution to the optical phase arising from a numerical solution of the laser rate equations as a frequency shift of the optical spectrum. The modulated optical signal can then meet the minimum-phase condition required by the KK algorithm. A system model is presented based on the direct modulation of a 10 Gb/s distributed feedback laser with 16-ary quadrature amplitude modulation (16-QAM) subcarrier modulation. The modulated signal is optically filtered, and a 53.5 Gb/s vestigial sideband signal is transmitted over 65 km of standard single-mode fiber. Dispersion compensation is applied after direct detection with a KK receiver. In addition, the impact of the optical filter parameters and receiver sampling rate on system performance are investigated.

中文翻译：

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使用带直接调制激光器的 Kramers-Kronig 接收器

摘要 Kramers-Kronig (KK) 接收器已被用于采用基于外部调制器的发射器的直接检测系统中的色散补偿。在本文中，我们研究了在基于直接调制激光器的直接检测系统中使用 KK 接收器进行色散补偿。我们通过将激光速率方程的数值解引起的对光学相位的线性贡献视为光谱的频移，来证明 KK 接收器的有效性。调制后的光信号可以满足 KK 算法要求的最小相位条件。系统模型基于具有 16 进制正交幅度调制 (16-QAM) 副载波调制的 10 Gb/s 分布式反馈激光器的直接调制。调制后的信号经过光学滤波，并通过 53. 5 Gb/s 残留边带信号通过 65 公里的标准单模光纤传输。在使用 KK 接收器直接检测后应用色散补偿。此外，还研究了光滤波器参数和接收器采样率对系统性能的影响。