In The Optical Fiber Stimulated Brillouin Scattering Based Slow Light Technology Research

Stimulated Brillouin scattering (SBS) is a nonlinear interaction between the pump and signal fields though an acoustic wave. Slow light based on SBS effect in optical fiber has many advantages, such as low power threshold, tunable operating wavelength, controllable time delay, and compatibility with existing optical communication system, etc; SBS slow light has many potential applications, for example, optically-controlled delay line, random-access memory, data synchronization and network buffering, and so on, which attracts many researchers. In the paper, the characteristics of SBS and slow light based on SBS have been studied. The contents are as follows:1. The background and progress of slow light based on SBS in optical fibers are introduced, as well as the methods and corresponding mechanisms to achieve slow light.2. The physical mechanism of slow light are explained making use of the Kramers-Kronig relations; Based on three-wave coupling equation, we obtain the relationship between the pulse delay and pulse broadening with the gain and explain the reasons of pulse broadening.3. The theory of SBS characteristics are studied and demonstrated experimentally. The major parameters of SBS characteristics are introduced; Based on single-band modulation technique, the measurement of the Brillouin gain spectrum and the gain coefficient are united effectively.4. Slow light based on SBS effect in optical fibers has been studied experimentally. Based on single-band modulation technique, SBS slow light are achieved in both single-mode fiber and photonic crystal fiber. Experimentally we obtain the pulse time delay and pulse broadening, and finally calculate the delay efficiency of the SMF and PCF according to the experimental result, which show that the delay efficiency of PCF is4.6times than that of SMF. Finally considering many other factors, especially the nonlinear coefficient and the delay efficiency, PCF is obviously suitable for SBS slow light medium.5. Broadband SBS slow light is discussed. The method of reducing pulse broadening is to increase the Brillouin gain bandwidth; Based on single-band modulation technique, a dual-gain pump structure is established in photonic crystal fiber.