Two measurement systems are developed for in-situ dielectric property measurement under high pressure in a wide-temperature range from 77K to 1273 K. The high-temperature system ranging from room temperature up to 127...Two measurement systems are developed for in-situ dielectric property measurement under high pressure in a wide-temperature range from 77K to 1273 K. The high-temperature system ranging from room temperature up to 1273K is equipped with a hexahedron anvils press, while the low-temperature system ranging from liquid nitrogen temperature to normal condition is equipped using the piston cylinder setup with a specially designed sample chamber. Using these configurations, the dielectric property measurement of ferroelectrie BaTiO3 and multiferroie Tm0.5Gd0.5MnO3 compounds are demonstrated, which proves the validity of the systems through the tuning of the polarization and phase transition boundary by high pressure. These two systems will be equally applicable to a wide variety of electronic and transport property measurements of insulators, semiconductors, as well as battery materials.展开更多
The nonlinear effects that limit the performance of the multi-frequency probe（MFP）based coherent optical time domain reflectometry（C-OTDR）are investigated.Based on theoretical analysis and experimental results,com...The nonlinear effects that limit the performance of the multi-frequency probe（MFP）based coherent optical time domain reflectometry（C-OTDR）are investigated.Based on theoretical analysis and experimental results,compared with conventional C-OTDR,when the probe pulse has power gradient within the pulse width,self-phase modulation（SPM）and cross-phase modulation（XPM）are strengthened in the new C-OTDR scheme.The generation of four-wave mixing（FWM）is dependent on SPM and XPM,and with modulation frequency of phase modulator higher than 40 MHz,the stimulated Brillouin scattering（SBS） threshold can be enhanced by more than 5 dB,which benefits the maximum dynamic range of the MFP C-OTDR.展开更多
基金Supported by the National Basic Research Program of China under Grant No 2009CB623301
文摘Two measurement systems are developed for in-situ dielectric property measurement under high pressure in a wide-temperature range from 77K to 1273 K. The high-temperature system ranging from room temperature up to 1273K is equipped with a hexahedron anvils press, while the low-temperature system ranging from liquid nitrogen temperature to normal condition is equipped using the piston cylinder setup with a specially designed sample chamber. Using these configurations, the dielectric property measurement of ferroelectrie BaTiO3 and multiferroie Tm0.5Gd0.5MnO3 compounds are demonstrated, which proves the validity of the systems through the tuning of the polarization and phase transition boundary by high pressure. These two systems will be equally applicable to a wide variety of electronic and transport property measurements of insulators, semiconductors, as well as battery materials.
基金supported by the National"973"Program of China(No.2010CB327803)the National Natural Science Foundation of China(Nos.61027617,60907022,and 60644001)
文摘The nonlinear effects that limit the performance of the multi-frequency probe（MFP）based coherent optical time domain reflectometry（C-OTDR）are investigated.Based on theoretical analysis and experimental results,compared with conventional C-OTDR,when the probe pulse has power gradient within the pulse width,self-phase modulation（SPM）and cross-phase modulation（XPM）are strengthened in the new C-OTDR scheme.The generation of four-wave mixing（FWM）is dependent on SPM and XPM,and with modulation frequency of phase modulator higher than 40 MHz,the stimulated Brillouin scattering（SBS） threshold can be enhanced by more than 5 dB,which benefits the maximum dynamic range of the MFP C-OTDR.
