Research On Slow And Fast Light In The Double-pump Excitation Tandem Erbium Fiber Structure

At present,with the continuous improvement of modern technology,optical fiber communication has become the main transmission method.And researchers are more and more interested in the research of the controllable speed of light.The popularity of fast and slow light of some materials has caused widespread attention to the propagation of fast and slow light.Based on practical applications,the focus of observing slow light and fast light has shifted to room temperature conditions and solid materials.In recent years,researchers have conducted a lot of research on the controllable speed of light.Fast light has become more and more popular.And many achievements have been made.Fast light can be used for super-light speed engines,detecting gravitational waves,improving the accuracy of gyroscopes,and controlling inertial forces.With the development of nonlinear optical devices,especially optical fibers containing trace elements,people have observed that the speed of light slows down in thulium-doped fiber,ytterbium-doped fiber,and erbium-doped fiber.However,there are still problems with optical buffering.At present,the use of the speed of light controllable principle,namely fast and slow light technology,can provide theoretical support for the optical buffering technology.In order to achieve the controllable speed of light,this paper uses Coherent Population Oscillation technology(CPO)to propose a new structure for studying fast and slow light at room temperature.This structure is 980 nm and 1480 nm pumped erbium fiber structure.Introduce from the following aspects:(1)An introduction to the development process of optical communications,the status of fast light and slow light research at home and abroad in recent years,as well as the content and innovation of this paper.(2)The structure and characteristics of the erbium-doped fiber are explained in detail,and the Kramers-Kronig dispersion is analyzed.And the absorption and dispersion curves of the medium are obtained from Kramers-Kronig dispersion;the mechanism of the CPO effect is emphatically studied to further understand the principle of controllable light speed.(3)The three-level structure of the erbium fiber and the rate equation of erbium ions are analyzed,and the theoretical formula of the speed of light in the double-pump series-connected erbium fiber structure is deduced,and the formula of time advance is deduced.(4)Based on the theory of coherent population oscillation,numerical simulation was performed to analyze the gain influence factors of the 980 nm and 1480 nm pumped erbium fiber structure;in addition,the 980 nm and 1480 nm pumped erbium fiber structure and single erbium were discussed.The influence of fiber single pump structure and single erbium fiber hybrid pump structure on slow light propagation and fast light propagation.Through data analysis,the large time delay and time advancement can be obtained in the 980 nm and 1480 nm pumped erbium fiber structure in series.And it is also found that the 980 nm and 1480 nm pumped erbium fiber structure has a stronger storage capacity.