Ding Yunhong, Hu Hao, Galili Michael, Xu Jing, Liu Liu, Pu Minhao, Mulvad Hans Christian Hansen, Oxenløwe Leif Katsuo, Peucheret Christophe, Jeppesen Palle, Zhang Xinliang, Huang Dexiu, Ou Haiyan
Wuhan National Laboratory for Optoelectronics, School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Opt Express. 2011 Mar 28;19(7):6471-7. doi: 10.1364/OE.19.006471.
A 640 Gbit/s NRZ OTDM signal has been successfully generated for the first time by format conversion of a 640 Gbit/s OTDM signal from RZ to NRZ. First, a coherent 640 Gbit/s OTDM RZ signal is generated by wavelength conversion of the original incoherent OTDM signal utilizing Kerr switching in a highly nonlinear fiber. Second, RZ-to-NRZ format conversion is achieved in a specially designed silicon microring resonator with FSR of 1280 GHz, Q value of 638, high extinction ratio and low coupling loss to optical fiber. A 640 Gbit/s NRZ OTDM signal with very clear eye-diagram and narrower bandwidth than both the original incoherent 640 Gbit/s and the wavelength converted coherent 640 Gbit/s RZ OTDM signals has been obtained. Bit error ratio measurements show error free (<10(-9)) performance at a received power of -30 dBm for all the OTDM channels of the 640 Gbit/s NRZ signal, with very low power penalty (<0.5 dB) and improved dispersion tolerance compared to the wavelength converted RZ case.
通过将640 Gbit/s的光时分复用（OTDM）信号从归零码（RZ）格式转换为非归零码（NRZ）格式，首次成功生成了640 Gbit/s的NRZ OTDM信号。首先，利用高非线性光纤中的克尔开关对原始非相干OTDM信号进行波长转换，生成一个相干的640 Gbit/s OTDM RZ信号。其次，在一个专门设计的硅微环谐振器中实现了从RZ到NRZ的格式转换，该谐振器的自由谱范围（FSR）为1280 GHz，品质因数（Q值）为638，具有高消光比和低光纤耦合损耗。已获得一个640 Gbit/s的NRZ OTDM信号，其眼图非常清晰，带宽比原始非相干640 Gbit/s和波长转换后的相干640 Gbit/s RZ OTDM信号都要窄。误码率测量表明，对于640 Gbit/s NRZ信号的所有OTDM通道，在接收功率为 -30 dBm时性能无误码（<10^(-9)），与波长转换后的RZ情况相比，功率代价非常低（<0.5 dB）且色散容限有所提高。
