A new detection system in scanning electron microscope,which filters in energy and detects the backscattered electrons close to the microscope axis,is described.This technique ameliorates the dependence of the back.sc...A new detection system in scanning electron microscope,which filters in energy and detects the backscattered electrons close to the microscope axis,is described.This technique ameliorates the dependence of the back.scat tering coefficient on atomic number,and suppresses effectively the relief contrast at the same time.Therefore this new method is very suitable to the composition analysis.展开更多
We report all-optical regeneration of the state of polarization of a 40 Gbit∕s return-to-zero telecommunication signal.The device discussed here consists of a 6.2-km-long nonzero dispersion-shifted fiber,with low po...We report all-optical regeneration of the state of polarization of a 40 Gbit∕s return-to-zero telecommunication signal.The device discussed here consists of a 6.2-km-long nonzero dispersion-shifted fiber,with low polarization mode dispersion,pumped from the output end by a backward propagating wave coming from either an external continuous source or a reflection of the signal.An initially scrambled signal acquires a degree of polarization close to 100%toward the polarization generator output.All-optical regeneration is confirmed by means of polarization and bit-error-rate measurements as well as real-time observation of the eye diagrams.We show that the physical mechanism underlying the observed four-wave-mixing-based polarization attraction phenomenon can be described in terms of the geometric approach developed for the study of Hamiltonian singularities.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.10045001.
文摘A new detection system in scanning electron microscope,which filters in energy and detects the backscattered electrons close to the microscope axis,is described.This technique ameliorates the dependence of the back.scat tering coefficient on atomic number,and suppresses effectively the relief contrast at the same time.Therefore this new method is very suitable to the composition analysis.
基金the European Research Council under the Grant Agreement 306633 PETAL ERC project,the CNRS,the Labex ACTION program(contract ANR-11-LABX-01-01)the Conseil Régional de Bourgogne under the PHOTCOM program.
文摘We report all-optical regeneration of the state of polarization of a 40 Gbit∕s return-to-zero telecommunication signal.The device discussed here consists of a 6.2-km-long nonzero dispersion-shifted fiber,with low polarization mode dispersion,pumped from the output end by a backward propagating wave coming from either an external continuous source or a reflection of the signal.An initially scrambled signal acquires a degree of polarization close to 100%toward the polarization generator output.All-optical regeneration is confirmed by means of polarization and bit-error-rate measurements as well as real-time observation of the eye diagrams.We show that the physical mechanism underlying the observed four-wave-mixing-based polarization attraction phenomenon can be described in terms of the geometric approach developed for the study of Hamiltonian singularities.
