We present a power-efficient and reduced-complexity all-optical approach to generate high-bit rate superchannels, based on joint time-frequency multiplexing. Both optical orthogonal frequency division multiplexing (OFDM) and Nyquist-optical time division multiplexing (N-OTDM) signals are generated and processed using a wavelength-selective switch (WSS). We use the fractional Fourier transform (FrFT) to introduce the largest degree of flexibility in optical networking, and we experimentally demonstrate that the transmitted signal can be received either in parallel, as OFDM subcarriers, or in series, as an N-OTDM signal. Compared to conventional optical OFDM, we achieve peak to average power ratio (PAPR) reduction; compared to N-OTDM, we introduce flexible chromatic dispersion (CD) management. We successfully demonstrate a field trial experiment of 4-channel 40 Gb/s hybrid OFDM/N-OTDM transmission over the 89.2-km Japan gigabit network-extreme (JGN X) test bed, with 1 bit/s/Hz spectral efficiency.

中文翻译：

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通过联合时频复用策略增强光通信

我们提出了一种基于联合时频复用的节能且复杂度降低的全光方法来生成高比特率超级信道。光正交频分复用 (OFDM) 和奈奎斯特光时分复用 (N-OTDM) 信号都是使用波长选择开关 (WSS) 生成和处理的。我们使用分数傅里叶变换 (FrFT) 在光网络中引入了最大程度的灵活性，并且我们通过实验证明了传输的信号可以作为 OFDM 子载波并行接收，也可以作为 N-OTDM 信号串联接收。与传统的光 OFDM 相比，我们实现了峰均功率比 (PAPR) 的降低；与 N-OTDM 相比，我们引入了灵活的色散 (CD) 管理。