Apodisation technology is introduced to optimize fiber Bragg grating based on the analysis of reflectivity spectrum and group delay response of fiber Bragg gratings. The characteristics of Hamming, Gauss and super-Gau...Apodisation technology is introduced to optimize fiber Bragg grating based on the analysis of reflectivity spectrum and group delay response of fiber Bragg gratings. The characteristics of Hamming, Gauss and super-Gauss functions are discussed and the optimization effects of the three apodisation functions on ripple smoothness of reflectivity spectrum,group delay and linear degree are compared respectively. As a result,the optimization effects of Hamming function is better than other two functions. When the bandwidth is less than ldB,Super-Gauss function is the best choice and proper parameters （G and m） of super-Gauss function can be selected expediently for wider bandwidth and better ripple smoothness of reflectivitv soectrum.展开更多
Many physical,chemical,and biological processes happen in liquid-vapor interface and are profoundly influenced with the local microstructures.In contrast to the liquid bulk,molecular orientation is the remarkable one ...Many physical,chemical,and biological processes happen in liquid-vapor interface and are profoundly influenced with the local microstructures.In contrast to the liquid bulk,molecular orientation is the remarkable one of asymmetric structural features of the interface.Here we report an experimental method,namely,electron-impact time-delayed mass spectrometry and give a Ion Detector Time-of-Flight Tub*Liquid Microjet Ion Attrac Liq Electron Multiplier Quadrupole Mass Filter Bender j id Beai Electrons Liquid Dump Pulsed Electron Gun brief review about our recent progresses.This brand-new method not only enables us to have more insights into the interfacial structures,as done with small-angle X-ray and neutron scatterings and vibrational sum frequency generation spectroscopy,but also provides opportunity to explore the electron-driven chemical reactions therein.展开更多
文摘Apodisation technology is introduced to optimize fiber Bragg grating based on the analysis of reflectivity spectrum and group delay response of fiber Bragg gratings. The characteristics of Hamming, Gauss and super-Gauss functions are discussed and the optimization effects of the three apodisation functions on ripple smoothness of reflectivity spectrum,group delay and linear degree are compared respectively. As a result,the optimization effects of Hamming function is better than other two functions. When the bandwidth is less than ldB,Super-Gauss function is the best choice and proper parameters （G and m） of super-Gauss function can be selected expediently for wider bandwidth and better ripple smoothness of reflectivitv soectrum.
基金This work is supported by the Ministry of Science and Technology of China(No.2017YFA0303502)the National Natural Science Foundation of China(No.21625301)We also thank Ling-ling Chen for her early contribution to the apparatus construction and Dr.Cen-feng Fu at University of Science and Technology of China for the theoretical simulations.
文摘Many physical,chemical,and biological processes happen in liquid-vapor interface and are profoundly influenced with the local microstructures.In contrast to the liquid bulk,molecular orientation is the remarkable one of asymmetric structural features of the interface.Here we report an experimental method,namely,electron-impact time-delayed mass spectrometry and give a Ion Detector Time-of-Flight Tub*Liquid Microjet Ion Attrac Liq Electron Multiplier Quadrupole Mass Filter Bender j id Beai Electrons Liquid Dump Pulsed Electron Gun brief review about our recent progresses.This brand-new method not only enables us to have more insights into the interfacial structures,as done with small-angle X-ray and neutron scatterings and vibrational sum frequency generation spectroscopy,but also provides opportunity to explore the electron-driven chemical reactions therein.
