Experimental Study On C+L-Band Tunable Multi-Wavelength Brillouin Erbium-Doped Fiber Laser

Multi-wavelength Brillouin erbium-doped fiber laser(MW-BEFL)is widely used in optical communication systems because of its narrow linewidth,low threshold and stable wavelength spacing.The appearance of wavelength division multiplexing(WDM)technology alleviates the tense situation of channel frequency resources in optical communication systems.However,the conventional carrier optical signal with frequency spacing of 10 GHz is not conducive to the decomposition of the optical signal at the receiving end of WDM systems,resulting in futrher requirements for the enhancement of multiple wavelength intervals in the output of wavelength lasers.In addition,along with the development of C-band MW-BEFL,the research of multi-wavelength fiber lasers expanded to L-band and 2um infrared band has attracted more and more researchers.In this thesis,the experimental study on the multi-wavelength fiber laser based on Brillouin effect is presented.The main contents are as follows:(1)The basic structure and characteristics of fiber lasers are briefly introduced as well as the research background and development of multi-wavelength fiber lasers.Finally,the main contents and innovations of this paper are described.(2)The theory of fiber laser,erbium-doped fiber amplifier(EDFA)and stimulated Brillouin scattering in fiber are introduced successively,and the structure and amplification characteristics of four kinds of erbium-doped fiber amplifiers are described.At last,some applications of Stimulated Brillouin Scattering are listed.(3)A MW-BEFL in L-band is designed,the effect of seed optical power and pump power on the number of output waves is studied through variable-controlling approach,and the effect of seed optical power on the WM-BEFL tuning range is particularly analyzed.The experimental results show that the MW-BEFL achieves 9 to 12 multi-wavelength outputs with a wavelength interval of0.089 nm in the tunable range of 14 nm to 17 nm at a given input power.(4)Based on the structure of "8"-shaped Brillouin fiber laser,the cascade effect of the linear cavity,the ring cavity and the cascade effect of the Brillouin scattering are used jointly to realize double,triple and quadruple frequency spacing responding to the wavelength interval of 0.16 nm,0.256 nm and 0.353 nm respectively.Besides,the output characteristics of multi-wavelength fiber lasers are studied experimentally.