Lorences-Riesgo Abel, Mazur Mikael, Eriksson Tobias A, Andrekson Peter A, Karlsson Magnus
Opt Express. 2016 Dec 26;24(26):29714-29723. doi: 10.1364/OE.24.029714.
We demonstrate and characterize an all-optical self-homodyne (SH) frequency superchannel enabled by comb regeneration at the receiver. In order to generate the superchannel, we use a frequency comb with 26 carriers spaced by 25 GHz at the transmitter, from which 24 carriers are modulated with polarization-multiplexed 32 quadrature amplitude modulation (PM 32-QAM) data. To enable comb regeneration at the receiver side, the two central carriers remain unmodulated. High fidelity comb regeneration is achieved by filtering the two unmodulated carriers with an approximately 25 MHz wide optical filter based on Brillouin amplification before a parametric mixer. The carriers from the regenerated comb are then used as local oscillator for SH detection. We demonstrate that all 24 carriers can be detected with an optical signal-to-noise ratio (OSNR) penalty lower than 2.5 dB in a back-to-back scenario. We also demonstrate that the whole superchannel can be transmitted through 120 km of single-mode fiber (SMF) and be detected with bit-error rate (BER) below 0.015.
我们展示并表征了一种通过接收机处的梳状再生实现的全光自外差（SH）频率超通道。为了生成超通道，我们在发射机处使用了一个具有26个载波、载波间隔为25 GHz的频率梳，其中24个载波用偏振复用32正交幅度调制（PM 32-QAM）数据进行调制。为了在接收机端实现梳状再生，两个中心载波保持未调制状态。在参数混频器之前，通过基于布里渊放大的约25 MHz宽的光学滤波器对两个未调制载波进行滤波，实现了高保真梳状再生。然后，将再生梳状信号中的载波用作SH检测的本地振荡器。我们证明，在背对背场景中，所有24个载波都可以在光信噪比（OSNR）损失低于2.5 dB的情况下被检测到。我们还证明，整个超通道可以通过120 km的单模光纤（SMF）进行传输，并在误码率（BER）低于0.015的情况下被检测到。
