The Fast Light And Sensing Of Double Brillouin Gain In Optical Fibers

In recent years,with the increasing development of internet,internet of things,artificial intelligence and so on,the demand for big capacity and large bandwidth transmission is increasing dramatically,which makes conventional optical-electricaloptical network transmission is unable to meet the requirement of information transmission.The all-optical communication network is becoming more urgently required.The all-optical communication network is limited by optical buffering and optical routing technology,and the controllable fast and slow light technology has unparalleled advantages in solving this problem.The stimulated Brillouin scattering fast and slow light in optical fibers has been extensively studied due to the advantages of operating at room temperature,being compatible with the current optical fiber communication system,and an adjustable bandwidth.The main content of this dissertation is as follows:Firstly,according to the dual-pump three-wave coupling equations,the transmission function,the Brillouin complex gain function and the time advancement are derived.The characteristics of double pump Brillouin gain in a conventional singlemode fiber and the theory of superluminal transmission of pulses between gain peaks are investigated by using the finite element method.The results show that when the frequency separation factor is greater than 0.596,double gain peaks can be observed.When the frequency separation factor is at the range of 1 to 5.25,fast light can be generated between the two gain peaks induced by the two pump waves.When the frequency is separated at 1.75,the maximum time advancement between the double pump Brillouin gain can reach up to 25 ps.When the frequency separation factor is 2.42,the normalized dispersion length corresponding to the third-order dispersion is infinite,and then the third-order dispersion is completely compensated.When the frequency separation factor is greater than 2.464,the pulse broadening factor approaches 1,this means that the distortionless pulses are transmitted in the fiber,but the time advancement is less than 13.52 ps.Then the temperature characteristics of the stimulated Brillouin scattering fast light in seven-core PCFs with different structures are studied,and the stimulated Brillouin scattering in the seven-core PCFs with different structures is simulated by the finite element method.The acousto-optic coupling efficiency,the effective refractive index,the effective mode field area,the Brillouin frequency shift,the Brillouin threshold and the time advancement are investigated when the air filling factor is 0.2,0.3,0.4 and the temperature varies from 20? to 80?.The results indicate that the effective refractive index,Brillouin frequency shift,and fast light time advancement increase linearly with increasing temperature for a proposed structure and a given pump power,and the coupling efficiency of the fundamental modes of the acoustic and optical field also increases,while the effective mode field area,Brillouin threshold,and pulse broadening factor decrease with the temperature increasing.In the case of a given temperature and pump power,the coupling efficiency and time advancement decrease with the increase of the air filling factor.