Opt Lett. 2018 Jun 1;43(11):2495-2498. doi: 10.1364/OL.43.002495.
We experimentally investigate the effects of erbium-doped fiber amplifier induced pump noise on soliton Kerr frequency combs for 64-quadrature amplitude modulation (QAM) transmission. We find that the optical carrier-to-noise ratios (OCNRs) of the comb lines across the C-band almost linearly depend on the pump OCNR and are similar for a constant input pump power and noise. For a specific three-soliton state, despite higher comb line power, there is no noticeable OCNR improvement compared to the single-soliton comb. When the ASE noise on the pump is varied by 10 dB in the stable single-soliton state, the comb linewidths remain relatively unchanged and similar to the pump linewidth. Furthermore, four lines of the single-soliton Kerr comb produced by a pump light at an OCNR larger than 52 dB are used as coherent light sources to transmit 20-Gbaud 64-QAM signals over a 25-km fiber with bit error rate below the forward-error correction threshold.
我们实验研究了掺铒光纤放大器诱导的泵浦噪声对用于 64 正交幅度调制 (QAM) 传输的孤子克尔频率梳的影响。我们发现，梳状线的光载波噪声比 (OCNR) 几乎随泵浦 OCNR 呈线性变化，且在恒定输入泵浦功率和噪声下，OCNR 相似。对于特定的三孤子状态，尽管梳状线功率较高，但与单孤子梳相比，OCNR 没有明显改善。在稳定的单孤子状态下，当泵浦上的 ASE 噪声变化 10dB 时，梳状线宽度保持相对不变，且与泵浦线宽相似。此外，在 OCNR 大于 52dB 的泵浦光作用下产生的单孤子克尔梳的四条线用作相干光源，在 25km 的光纤中传输 20Gbaud 64-QAM 信号，误码率低于前向纠错阈值。
