We experimentally demonstrate Kramers–Kronig detection of four 20 Gbaud 16-quadrature-amplitude-modulated (QAM) channels after 50 km fiber transmission using two soliton Kerr combs as signal sources and local oscillators. The estimated carrier phase at the receiver for each of the channels is relatively similar due to the coherence between the frequency comb lines. The standard deviation of the estimated carrier phase difference of the channels is less than 0.08 rad after 50 km single-mode fiber (SMF) transmission. This enables the carrier phase recovery derived from one channel to be shared among multiple channels. In the back-to-back scenario, the bit error rate (BER) performance for shared carrier phase recovery shows an optical signal-to-noise ratio penalty of ${\sim}{0.5}\;{\rm dB}$ compared to the BER performance for carrier phase recovery when derived for each channel independently. BERs below the forward error correction threshold are achieved after 50 km SMF transmission with both independent and shared carrier phase recovery for four 20-Gbaud 16-QAM signals.

中文翻译：

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Kramers–Kronig使用Kerr梳对四个20 Gbaud 16-QAM通道进行检测，以进行共享相位估计

我们通过实验证明，使用两个孤子Kerr梳子作为信号源和本地振荡器，在光纤传输50 km后，对四个20 Gbaud 16正交幅度调制（QAM）信道进行Kramers–Kronig检测。由于频率梳线之间的相干性，每个信道的接收机处的估计载波相位相对相似。在50 km单模光纤（SMF）传输之后，信道的估计载波相位差的标准偏差小于0.08 rad。这使得源自一个信道的载波相位恢复能够在多个信道之间共享。在背对背方案中，共享载波相位恢复的误码率（BER）性能显示出光信号的信噪比损失为{{\ sim} {0.5} \; {\ rm dB} $与针对每个通道独立得出的用于载波相位恢复的BER性能进行比较。在50 km SMF传输后，对于四个20 Gbaud 16-QAM信号，具有独立和共享载波相位恢复，即可实现低于前向纠错阈值的BER。