Investigation And Application Of Stimulated Brillouin Scattering Slow Light In Double-clad Photonic Crystal Fibers

In recent years,with the rapid development of optical communication technology,ultra-high-speed and large-capacity optical fiber communication are increasing needed,thus all-optical communication network is the inevitable choice of next generation communication technology.The optical buffering and optical routing are the key technologies for realizing all-optical network.So far,there is no mature technology and application for realizing optical buffering and optical routing.Controllable fast and slow light technology is one of the potential technologies to achieve optical buffering.Fast and slow light based on stimulated Brillouin scattering in optical fibers have attracted considerable attention due to its flexible wavelength adjustment,operating at room temperature and so on.In this dissertation,the effects of structure on slow light properties via stimulated Brillouin scattering in double-clad As₂Se₃ chalcogenide photonic crystal fiber are proposed and investigated by the finite element method.Temperature response of slow light in liquid filled double-clad photonic crystal fibers is demonstrated.The main contents and achievements are as follows:The effects of inner cladding and outer cladding structures on slow light properties based on stimulated Brillouin scattering in double-clad As₂Se₃ chalcogenide photonic crystal fiber are investigated by taking into account high-order acoustic modes.The results indicate that the air filling fraction of the inner cladding affects the properties of slow light more easily than air filling fraction of the outer cladding dose,and the Brillouin gain spectrum presents two peaks structure.The main peak of Brillouin gain spectrum decreases gradually,the second peak increases gradually,the time delay and the Brillouin gain increases with the increasing of air filling fraction of the inner cladding.The time delay upto 705ns and Brillouin gain upto 40dB can be achieved by pumped with 10mW in a 1-m-long fiber when the air filling fraction of the inner cladding is 0.9.But these properties of slow light are less affected by the variation of the air filling fraction of the outer cladding,because the outer cladding restricts the acoustic modes only when the diameter of the air hole in the inner cladding is small enough.Therefore,the properties of slow light induced in double-clad As₂Se₃ chalcogenide PCF are more affected by the air filling fraction of the inner cladding.And comparing with inner cladding,these properties are less affected by the air filling fraction of the outer cladding.The temperature sensitivity of slow light in the photonic crystal fiber is improved by inserting small air hole cladding near the core and filled with liquid.The acousto-optic coupling efficiency,effective refractive index,effective mode area,Brillouin frequency shift,Brillouin threshold,gain,time delay of slow light and pulse broadening factor varying with the temperature between 20? and 80? filled with alcohol and water are analyzed,respectively.The results indicate that the acousto-optic coupling efficiency,Brillouin frequency shift,gain,time delay and pulse broadening factor increases and the effective mode area and Brillouin threshold decrease as the temperature goes up,because the effect of stimulated Brillouin scattering enhanced after filled with liquid.The effective refractive index increases with the increasing of temperature after filled with water,but it decreases when filled with alcohol.The maximum time delay of 47.5ns and 50.3ns by filled with alcohol and water respectively when the temperature is 80?.