为了解决受激布里渊散射快光在高吸收区产生损耗的问题, 通过分析普通单模光纤中双线泵浦产生的双布里渊增益线特性及在增益峰间实现脉冲的超光速传输理论, 利用有限元法数值模拟了双布里渊增益线处受激布里渊散射引起的快光特性。结果表明, 当频率分离因子大于0.596时, 可以观察到双增益峰; 当频率分离因子在1~5.25范围内时, 两个泵浦波产生的双增益峰之间可以明显地产生快光; 当频率分离因子为1.75时, 在双布里渊增益线之间的最大时间提前可达25 ps。当频率分离因子为2.42时, 三阶色散所对应的归一化色散长度为无穷大, 三阶色散可以得到完全补偿; 当频率分离因子大于2.464时, 脉冲展宽因子趋近于1, 可以实现无畸变传输, 但时间提前量小于13.52 ps。本文的研究结论对于在布里渊增益区实现快光具有一定的理论意义, 并对设计基于受激布里渊散射快光器件具有理论指导作用。

In order to solve the problem that the stimulated Brillouin scattering fast light which occurs in the high absorption region decays rapidly, fast light via stimulated Brillouin scattering at double Brillouin gain line in an optical fiber is described and numerically simulated. The simulation results show that the fast light occurs between the double gain peaks induced by two pump waves when the frequency separation factor is at the range of 1-5.25, and the maximum time advancement is up to 25 ps between the doublet Brillouin lines when the frequency separation is 1.75. The double gain peaks can be observed when the frequency separation factor is larger than 0.596. The three-order dispersion (TOD) can complete compensation in the frequency separation factor range of 1-5.25. The dispersion relation can be represented by the normalized dispersion length Lm. As the separation factor is 2.42, the Lm of TOD is infinite that expressed the TOD being fully compensated. The pulse broadening factor is 0.986 and the time advancement is 13.52 ps at the separation factor of 2.464. The pulse broadening factor is close to 1 when the frequency separation factor being larger than 2.464, and the time advancement is less than 13.52 ps. The research conclusions have certain theoretical significance for the realization of fast light in the Brillouin gain region, and have theoretical reference for designing optical devices based on stimulated Brillouin scattering fast light.