Kakkar Aditya, Schatz Richard, Pang Xiaodan, Navarro Jaime Rodrigo, Louchet Hadrien, Ozolins Oskars, Jacobsen Gunnar, Popov Sergei
Opt Express. 2015 May 4;23(9):11221-6. doi: 10.1364/OE.23.011221.
A theoretical investigation of the equalization-enhanced phase noise (EEPN) and its mitigation is presented. We show with a frequency domain analysis that the EEPN results from the non-linear inter-mixing between the sidebands of the dispersed signal and the noise sidebands of the local oscillator. It is further shown and validated with system simulations that the transmission penalty is mainly due to the slow optical frequency fluctuations of the local oscillator. Hence, elimination of the frequency noise below a certain cut-off frequency significantly reduces the transmission penalty, even when frequency noise would otherwise cause an error floor. The required cut-off frequency increases linearly with the white frequency noise level and hence the linewidth of the local oscillator laser, but is virtually independent of the symbol rate and the accumulated dispersion.
本文对均衡增强型相位噪声（EEPN）及其抑制方法进行了理论研究。通过频域分析表明，EEPN是由色散信号边带与本地振荡器噪声边带之间的非线性混频产生的。系统仿真进一步表明并验证了传输代价主要是由于本地振荡器的缓慢光频率波动。因此，即使频率噪声否则会导致误码平台，消除低于某个截止频率的频率噪声也能显著降低传输代价。所需的截止频率随白频率噪声水平以及本地振荡器激光器的线宽线性增加，但实际上与符号率和累积色散无关。
