Study On Raman Fiber Amplifiers And Multiwavelength Raman Fiber Lasers

Based on the principle of Stimulated Raman Scattering (SRS) in fiber, the dissertation is focused on the study of Raman fiber amplifiers and multiwavelength Raman fiber lasers.Based on the theory of average power analysis, a new matrix iterative method for the wideband Raman fiber amplifier was presented. The distributed Raman fiber amplifier was developed, which can be put into practical use in DWDM systems. With 60km transmission distance, it has an average on-off gain of 17.89dB, a average effective noise figure of–2.60dB, a average polarization-dependent gain of 0.17dB, a gain flat of 1.57dB and a amplification bandwidth of 80nm. Besides, a distributed Raman amplifier with a novel pump scheme was studied experimentally.For the first time, as far as we know, a novel wideband discrete Raman fiber amplifier was presented, which is named as wideband double-pass discrete Raman amplifier. Its characteristics of gain, noise and polarization-dependent gain were studied theoretically and experimentally. The results showed that this configuration could obviously improve the gain efficiency by two or three times.A multiwavelength Raman fiber laser was presented for the first time, as far as we know. The characteristics of multiwavelength fiber ring laser can be easily controlled by adjusting the parameters of the sampled Bragg grating, including the sampling period and the sampling length. In the proposed fiber laser, stable 4 oscillating wavelengths with 100GHz and 50GHz spacing have been achieved, respectively, as well as 5 oscillating ones with a wavelength spacing of only 25GHz by varying the sampling period of the SBG.. Besides, the multiwavelength Raman laser based on Fabry–Perot etalon was studied experimentally.