With the aim of using a single laser per transceiver in single fiber splitter-based passive optical networks (PON) with coherent homodyne receivers, we apply wavelength shifting in an ultra-dense wavelength division multiplexing (UD-WDM) scheme. The studied architecture is based on a dual-parallel Mach-Zehnder Modulator (DP-MZM) operating in carrier-suppressed single-sideband (CS-SSB). In this configuration, a single laser feeds both the coherent homodyne receiver, and the transmitter, simplifying the wavelength management in the PON. The modulator carries out both data modulation and wavelength shifting. In this study, a bit rate of 4 Gb/s in QPSK is used to test several roll-off factors and channel spacing configurations. The results show that power budget gains of 18 dB are achievable with a channel spacing equal to only the symbol rate.

中文翻译：

---

使用UD-WDM的单激光器Homodyne收发器中的瑞利背向散射抑制 λ-换档

为了在具有相干零差接收器的基于单光纤分束器的无源光网络（PON）中为每个收发器使用单个激光器，我们在超密集波分复用（UD-WDM）方案中应用了波长偏移。研究的体系结构基于在载波抑制的单边带（CS-SSB）中运行的双并行马赫曾德尔调制器（DP-MZM）。在这种配置中，单个激光器既可以为相干零差接收器提供信号，也可以为发送器提供信号，从而简化了PON中的波长管理。调制器既执行数据调制又执行波长转换。在这项研究中，QPSK中的4 Gb / s比特率用于测试多个滚降因子和通道间隔配置。结果表明，在信道间隔仅等于符号率的情况下，可以实现18 dB的功率预算增益。