This work reports on the use of a gain-switched vertical cavity surface-emitting laser (VCSEL) optical frequency comb (OFC) to generate multiple optical carriers for applications in future wavelength-division multiplexing (WDM) passive optical network (PON) systems. The VCSEL-based OFC system was tested for its ability to simultaneously transmit error-free data signals up to 30 Gbps, and a 50 MHz clock signal proposed to be used for latency monitoring of the network. The system was demonstrated over a fiber distance beyond 20 km. Four optical carrier signals were filtered from the generated OFC. Three of the four optical carriers were combined and amplitude-modulated with 5 and 10 Gbps on–off keying (OOK) data signals. The fourth optical carrier was amplitude-modulated with a 50 MHz clock signal. These four modulated optical carriers were multiplexed and transmitted over 21 km of standard single-mode fiber. When the three data-carrying optical carriers were modulated with 5 Gbps OOK data and multiplexed with the clock-carrying carrier, a negligible transmission penalty was achieved after fiber transmission. When these three data-carrying optical carriers were modulated with 10 Gbps OOK data and multiplexed with a clock-carrying carrier, a maximum transmission penalty of 4.8 dB was achieved after fiber transmission. The system was investigated at a minim bit error rate (BER) of ${{10}^{- 9}}$. A receiver sensitivity of less than ${-}{11}\;{\rm dBm}$ was achieved at both bit rates. The clock signal suffered little effect when transmitted with the three optical carriers at both 5 and 10 Gbps data rate. A power penalty of 15.37 dB, mainly due to fiber attenuation, was experienced in the clock after fiber transmission. Due to the unavailability of the numerical system to quantify the clock performance in terms of phase noise, the phase-noise results could not be provided. Nevertheless, the provided qualitative results were able to show that the transmitted clock integrity was able to be retained after being multiplexed with transmission on the 21 km fiber channel. For the first time, to the best of our knowledge, we have simultaneously reported on data and clock transmission results using a low-power, VCSEL-based OFC to realize a WDM-PON system. These results are attractive as they demonstrate and motivate the possibility of using gain-switched VCSELs as OFC sources in future WDM-PON networks requiring enhanced channel capacity and stringent network latency monitoring to realize intelligent, simple, and power-efficient PON networks.

中文翻译：

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在光子辅助WDM无源光网络中同时传输时钟和数据信号

这项工作报告了如何使用增益转换垂直腔表面发射激光器（VCSEL）光学频率梳（OFC）生成多个光载波，以用于未来的波分复用（WDM）无源光网络（PON）系统。对基于VCSEL的OFC系统进行了测试，它可以同时传输高达30 Gbps的无错误数据信号的能力进行了测试，并且建议将50 MHz时钟信号用于网络的延迟监视。该系统在超过20 km的光纤距离上进行了演示。从产生的OFC中过滤出四个光学载波信号。四个光载波中的三个被合并并通过5和10 Gbps开关键控（OOK）数据信号进行幅度调制。第四光学载波用50 MHz时钟信号进行幅度调制。这四个调制的光载波被多路复用并在21 km的标准单模光纤上传输。当使用5 Gbps OOK数据调制这三个数据承载光学载波并与时钟承载载波进行多路复用时，在光纤传输之后，传输损失可忽略不计。当使用10 Gbps OOK数据调制这三个数据承载光载波并与时钟承载载波多路复用时，在光纤传输之后，最大传输损失为4.8 dB。对系统的最小误码率（BER）为 当使用10 Gbps OOK数据调制这三个数据承载光载波并与时钟承载载波多路复用时，在光纤传输之后，最大传输损失为4.8 dB。对系统的最小误码率（BER）为 当使用10 Gbps OOK数据调制这三个数据承载光载波并与时钟承载载波多路复用时，在光纤传输之后，最大传输损失为4.8 dB。对系统的最小误码率（BER）为$ {{10} ^ {-9}} $。接收机灵敏度小于$ {-} {11} \; {\ rm dBm} $两种比特率都可以实现。当与三个光学载波以5 Gbps和10 Gbps的数据速率传输时，时钟信号几乎没有影响。光纤传输后的时钟中经历了15.37 dB的功率损失，这主要归因于光纤衰减。由于数值系统无法根据相位噪声来量化时钟性能，因此无法提供相位噪声结果。但是，提供的定性结果能够表明，在与21 km光纤通道上的传输复用之后，仍可以保留所传输的时钟完整性。据我们所知，这是第一次，我们同时使用基于VCSEL的低功耗OFC来实现WDM-PON系统，同时报告了数据和时钟的传输结果。