The Study Of Control Optical Speed Based On Stimulated Brillouin Scattering In Optical Fiber

The Electric-light， light-electric conversion in the opticalcommunication network limits the improvement of speed ofcommunication network. All-Optical communication network requiresoptical routing and optical switching devices. The signal synchronizationand cache in optical communication network can be achieved if the speedof light can be effectively controlled. So the optical routing and switchingtechnology can be used to solve the bottleneck of all-opticalcommunication. The control of light speed in fiber includes slow lightand fast light. Stimulated Brillouin scattering is an effective way tocontrol the speed of light because of its room temperature operability,compatibility with the communication network and large amount of delay.The control of light speed based on stimulated Brillouin scattering hasbeen studied in this paper, detailed research works are as follows:1. The research background and technical solutions are introduced. The optical speed control based on electromagnetic induced transparencytechniques, coherent population oscillation technique, stimulated Ramanscattering, optical parametric amplification were analyzed and discussed.The physical mechanism and characteristics of stimulated Brillouinscattering, the theory of optical speed control are introduced too. Theadvancement on control of light speed based on stimulated Brillouinscattering in optical fibers is presented.2. The theory of change the optical group velocity is explained, and it isintroduced that the way to change group velocity in the fiber based onstimulated Brillouin scattering. Stimulated Brillouin scattering coupledwave equations are derived and Fourier transformed to calculate the gain,refractive index and group index of fiber. The control of light speed undersmall-signal gain is simulated and the relationship between gain, delayand pump power is analyzed. The research shows that the delay andbroadening factor of light pulse increases with increasing pump power.3. The optical experimental platform is built. The backward scatteredlight which is tailored by band-pass filter is used as pump light. Changethe center wavelength of the band-pass filter can make us get differentpump light. So the fast light and slow light can be achieved in the samesystem. Finally， the experimental results were analyzed and therelationship between delay time and pump power was studied.