A temperature independent 80-Gb/s 100-km transmission system is demonstrated with the use of spectral phase modulation-based tunable dispersion compensator （TDC）. The principle of dispersion compensation based on sp...A temperature independent 80-Gb/s 100-km transmission system is demonstrated with the use of spectral phase modulation-based tunable dispersion compensator （TDC）. The principle of dispersion compensation based on spectral phase modulation as well as the relationship between spectral phase modulation function and group velocity dispersion （GVD） are theoretically studied. TDC based on spectral phase modulation is implemented. The performance of 80-Gb/s transmission system is experimentally evaluated. The non- linear relationship between temperature and temperature-induced dispersion fluctuations is demonstrated through the asymmetric temperature-induced power penalty without dispersion compensation. With respect to the low temperature area, the temperature-induced dispersion fluctuations are smaller than those in the high temperature area. By using the proposed TDC, temperature independent 80-Gb/s transmission is successfully demonstrated under a temperature range of -20 60 ℃ with a power penalty of less than 0.8 dB.展开更多
The phase field crystal （PFC） model is used to simulate the premelting dislocation movement of the symmetric tilt grain boundary （STGB） under strain action when the system temperature is at far from the melting po...The phase field crystal （PFC） model is used to simulate the premelting dislocation movement of the symmetric tilt grain boundary （STGB） under strain action when the system temperature is at far from the melting point and close to the melting point, respectively. The results show a local premelting occurs surrounding the dislocations as the premelting temperature is approached to from below temperature. The premelting dislocations of the STGB can glide under strain action, and the premelting region is a companion for dislocation gliding. The process of STGB decay is very similar at the two high temperature conditions. As premelting presents, it diminishes the gliding resistance for the dislocations and leads to a faster movement of dislocations, and also brings about more energy reduction of the system during the decay process of STGB. In spite of applying strain to these premelting samples in whole decay processes of STGB, the premelting dislocation region does not obviously develop and extend. This indicates that the external strain action does not promote the premelting at the high temperature, and cannot induce more premelting dislocation, which can be owed to the premelting phase around the dislocation exhibit fluid-like properties and to the premelting dislocation easily gliding and relaxing the strain energy; this is in agreement with the results of experiments and molecular dynamics.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,Beijing Jiaotong University (No. 2009YJS005)the National "863" Program of China (Nos. 2007AA01Z258 and 2008AA01Z15)+1 种基金the National Natural Science Foundation of China (Nos.60577034, 60747002, 60837003, and 60877042)the Beijing Nova Program (No. 2008A026)
文摘A temperature independent 80-Gb/s 100-km transmission system is demonstrated with the use of spectral phase modulation-based tunable dispersion compensator （TDC）. The principle of dispersion compensation based on spectral phase modulation as well as the relationship between spectral phase modulation function and group velocity dispersion （GVD） are theoretically studied. TDC based on spectral phase modulation is implemented. The performance of 80-Gb/s transmission system is experimentally evaluated. The non- linear relationship between temperature and temperature-induced dispersion fluctuations is demonstrated through the asymmetric temperature-induced power penalty without dispersion compensation. With respect to the low temperature area, the temperature-induced dispersion fluctuations are smaller than those in the high temperature area. By using the proposed TDC, temperature independent 80-Gb/s transmission is successfully demonstrated under a temperature range of -20 60 ℃ with a power penalty of less than 0.8 dB.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 51161003）, the Natural Science Foundation of Guangxi Province （Grant No. 2012GXNSFDA053001） and Ministry-Province Jointly-Constructed Cultivation Base for State Key Laboratory of Processing for Non-Ferrous Metal and Featured Materials, Guangxi Zhuang Autonomous Region （Grant No. GXKFJ12-01）.
文摘The phase field crystal （PFC） model is used to simulate the premelting dislocation movement of the symmetric tilt grain boundary （STGB） under strain action when the system temperature is at far from the melting point and close to the melting point, respectively. The results show a local premelting occurs surrounding the dislocations as the premelting temperature is approached to from below temperature. The premelting dislocations of the STGB can glide under strain action, and the premelting region is a companion for dislocation gliding. The process of STGB decay is very similar at the two high temperature conditions. As premelting presents, it diminishes the gliding resistance for the dislocations and leads to a faster movement of dislocations, and also brings about more energy reduction of the system during the decay process of STGB. In spite of applying strain to these premelting samples in whole decay processes of STGB, the premelting dislocation region does not obviously develop and extend. This indicates that the external strain action does not promote the premelting at the high temperature, and cannot induce more premelting dislocation, which can be owed to the premelting phase around the dislocation exhibit fluid-like properties and to the premelting dislocation easily gliding and relaxing the strain energy; this is in agreement with the results of experiments and molecular dynamics.
