Shimizu Satoshi, Cincotti Gabriella, Wada Naoya
Opt Express. 2017 Feb 20;25(4):3496-3503. doi: 10.1364/OE.25.003496.
We have proposed and experimentally demonstrated all-optical multiplexing (MUX)-format conversion from Nyquist optical time division multiplex (OTDM) to Nyquist wavelength division multiplex (WDM). The system is simply configured with a straight-type phase modulator (PM) driven by a sinusoidal wave and an optical Nyquist filter. In the theoretical investigation, it is proved that the single Nyquist signal is completely converted to Nyquist WDM signal, which consists of two half-baud-rate signals with different carrier frequencies. The theoretical modulation voltage for the phase modulator is slightly lower than Vπ: 0.913 Vπ, and it is experimentally verified. In the experimental demonstrations, 50 Gbaud to 25 Gbaud x 2 and 25 Gbaud to 12.5 Gbaud x 2 conversions are successfully demonstrated with quite low optical signal-to-noise ratio (OSNR) penalties. In addition, cascaded MUX-format conversion is also demonstrated; 50 Gbaud Nyquist signal is converted to four channels of 12.5 Gbaud Nyquist signals.
我们已经提出并通过实验证明了从奈奎斯特光时分复用（OTDM）到奈奎斯特波分复用（WDM）的全光复用（MUX）格式转换。该系统仅由一个由正弦波驱动的直型相位调制器（PM）和一个光学奈奎斯特滤波器简单配置而成。在理论研究中，证明了单个奈奎斯特信号被完全转换为奈奎斯特WDM信号，该信号由两个具有不同载波频率的半波特率信号组成。相位调制器的理论调制电压略低于Vπ：0.913Vπ，并且通过实验得到了验证。在实验演示中，成功演示了50G波特到25G波特×2以及25G波特到1·5G波特×2的转换，且光信噪比（OSNR）惩罚相当低。此外，还演示了级联MUX格式转换；50G波特奈奎斯特信号被转换为四个通道的12.5G波特奈奎斯特信号。
