The Tunable Slow Light Based On Nonlinear Optical Fiber

With the exponential growth of communication requirement and the fast development of Optical Fiber Communication, Slow light draws a great of interests. Especially, slow light based on Stimulated Brillouin scattering (SBS) shows possibility to achieve the practical application. Nonlinear fiber has excellent performance in SBS for its high nonlinearity, and it has great significance to research the SBS slow light based on the nonlinear fiber.First of all, Based on the optical fiber doped with nano-material InP, the characteristics of SBS slow light in this nonlinear fiber are concluded. Calculate the SBS model in this fiber, a considerable time delay of-738ps is obtained, which shows much strong SBS process and energy diversion in shorter length than single mode fiber under the same conditions.Based on the analyze mentioned above, experimental systems are set up to measure the slow light parameter. The results shows the Brillouin threshold of 1km nonlinear fiber is 17.8dBm/60mw. The Brillouin gain spectrum width is 65MHz, which is more wider and stable than that in single mode fiber(36MHz). The measured unit Brillouin maximum peak power(0.032mw/km) is greater than the value of single-mode fiber.By setting up three different experimental systems to compare and analyze the performance of pump light and signal light matching, the manual matching method is finally chosen into the SBS slow light system based on the nonlinear fiber. when the input signal pulse is 1555.8174nm(140ns), a maximum time delay of 8ns is obtained. With fixed wavelength, the signal delay increases with increasing pump power, compared with the delay under input 17.8dBm, the value is about 4ns more under 18.5dBm input.Based on the research above, a conclusion is achieved, that due to the strong restrictive effect of the fiber mode field and the higher non-uniformity, the slow light in nonlinear fiber is enhanced. Meanwhile, the Brillouin gain spectrum width is expanded, which leads a wider range of effective slow light. Moreover, the more stable gain spectra is conducive for the realization.Finally, the signal distortion and pulse aberrance are discussed. Then research broadening Brillouin gain spectrum methods to reduce the transmission distortion, which leads a way for continuous research in this project, moreover, establishes the foundation for the practical application of the slow light based on nonlinear optical fiber.