设计了一种基于四阶脉冲幅度调制(PAM4)技术的50 Gbit/s 40 km QSFP28封装的长距离光传输模块,以应对现代社会对通信传输的带宽、速率和容量等要求的不断增长。使用了PAM4技术以提高单波长的数据传输容量,使得单波传输速率达到50 Gbit/s...设计了一种基于四阶脉冲幅度调制(PAM4)技术的50 Gbit/s 40 km QSFP28封装的长距离光传输模块,以应对现代社会对通信传输的带宽、速率和容量等要求的不断增长。使用了PAM4技术以提高单波长的数据传输容量,使得单波传输速率达到50 Gbit/s;在模块的接收单元使用雪崩光电二极管(APD)作为光探测器,使得模块对小光信号的接收能力得到提高;测试结果表明,模块的性能较为稳定,优化了APD部分电路设计,以获得更佳的传输效果,能够满足50 GE 40 km传输。展开更多
The phonon spectrum of ordered zincblende Si50Ge50 alloy is calculated by ab initio method. The energy band structure at zero pressure and the pressure dependence of phonon dispersion curves are shown up to 20 GPa. Th...The phonon spectrum of ordered zincblende Si50Ge50 alloy is calculated by ab initio method. The energy band structure at zero pressure and the pressure dependence of phonon dispersion curves are shown up to 20 GPa. The calculation finds a pressure-induced softening of the transverse acoustic phonon mode and the mode frequency reaching zero at about 14 GPa, which indicate breaking of the symmetry and formation of a new phase under high pressure.展开更多
文摘设计了一种基于四阶脉冲幅度调制(PAM4)技术的50 Gbit/s 40 km QSFP28封装的长距离光传输模块,以应对现代社会对通信传输的带宽、速率和容量等要求的不断增长。使用了PAM4技术以提高单波长的数据传输容量,使得单波传输速率达到50 Gbit/s;在模块的接收单元使用雪崩光电二极管(APD)作为光探测器,使得模块对小光信号的接收能力得到提高;测试结果表明,模块的性能较为稳定,优化了APD部分电路设计,以获得更佳的传输效果,能够满足50 GE 40 km传输。
基金Supported by the National Natural Science Foundation of China (Grant No. 50771090)the State Key Program for Basic Research of China (Grant No. 2005CB724404)the Program for Changjiang Scholars and Innovative Team (Grant No. IRT0650)
文摘The phonon spectrum of ordered zincblende Si50Ge50 alloy is calculated by ab initio method. The energy band structure at zero pressure and the pressure dependence of phonon dispersion curves are shown up to 20 GPa. The calculation finds a pressure-induced softening of the transverse acoustic phonon mode and the mode frequency reaching zero at about 14 GPa, which indicate breaking of the symmetry and formation of a new phase under high pressure.
