Theoretical Research And Experimental Test For L-band Multi-wavelength Fiber Laser

With the requirements of Internet transmission and capacity are higher and higher in our daily life and work,the dense wavelength division multiplexing(DWDM)technology has been developed rapidly.Furthermore,as one of the key technologies for DWDM systems,the multi-wavelength fiber laser has gained wide attention at home and abroad.At present,along with the increasingly extensive application of the L-band multi-wavelength fiber laser.In this paper,the multi-wavelength fiber laser based on L-band is researched comprehensively and some innovations are proposed actively.The main contents include:(1)First of all,the background of this task is introduced.Then the development and applications of fiber lasers and multi-wavelength fiber lasers are illustrated respectively.At last,the main content and innovative points of this thesis are given.(2)The basic theory of fiber lasers is presented in detail at first and followed by the filtering technique and frequency stabilization technique which both are the critical technologies of the multi-wavelength fiber laser.Lastly,three kinds of multi-wavelength fiber lasers are described through the theoretical analysis.(3)The deep theory analysis and relative simulations of the filter technologies which separately make use of Sagnac loop filter,Mach-Zehnder interferometer and Bragg grating filter in multi-wavelength fiber lasers are made to build up the basis of innovations.(4)Two novel multi-wavelength fiber lasers are proposed and demonstrated.One is a linear cavity erbium-doped fiber laser based on a nonlinear optical loop mirror(NOLM)and cascaded filtering of Sagnac loop and Mach-Zehnder(M-Z)filter.Compare with the Sagnac loop filter and M-Z interferometer,the filter property of this new laser is much superior,which can output 19 wavelengths steadily with the SMSR average of 30 dB at room temperature.The other design is an L-Band linear cavity tunable multi-wavelength erbium-doped fiber(EDF)laser based on nonlinear optical loop mirror(NOLM)and dual-channel Mach-Zehnder interferometer(MZI)interferometer.In addition,it proved that the filter of this laser is more efficient than the single-channel M-Z interferometer.As a result,stable wavelengths(wavelength drift less than 0.05 nm and power fluctuation less than0.2 dB)are achieved at room temperature and the SMSR is up to 40 dB.