The Generation And Amplification Of Multistability Phenomena In Fiber Laser By Using The Nonlinear Polarization Rotation Technique

Fiber laser is extensively used in optical communication, optical sensing, laser technology and so on. By using the nonlinear polarization rotation technique, the fiber laser can operate with tunable wavelength, multiwavelength, or mode-locked. Thus the fiber laser attracts most researchers because of their many advantages, such as structure compact, a good beam quality, a high coupling efficiency and a low price. In this dissertation, we theoretically and experimentally studied the generation of multistability phenomena in the same resonance based on the nonlinear polarization rotation, and we have also studied the amplifier of those multistability phenomena. The main contents are as follows:1. Based on the nonlinear polarization rotation, we have theoretically analyzed the generation mechanism of the tunable continuous wave, by adjusting the polarization controller, we have obtained different center wavelengths operation of the fiber laser, and we have also obtain different output power with the same center wavelength. 2. According to equation of the mode-locked fiber laser, we detailed discussed effects of the dispersive, the self-phase modulation and the self-amplitude modulation on the mode-locked laser. Using the general nonlinear couple Schr?dinger equation, we have analyzed the generation mechanism of the mode-locked. Using the distribution Fourier numerical simulation, the mode-locked pulses and the bound soliton pulses have also been obtained respectively by solving the general nonlinear couple Schr?dinger equation.3. Using the nonlinear polarization rotation technique, we have experimentally obtained multistability phenomena in an erbium-doped fiber ring laser: (i) a wavelength continuously tunable laser (CTL), (ii) normal soliton pulses and (iii) bound soliton pulses. The CTL has a tuning range of 25.7 nm, from 1532.16nm to 1557.86nm, the side-mode suppression ratio of more than 35 dB and the 3-dB spectral less than 0.1nm. The normal soliton pulses have a repetition rate of 14.3 MHz, central wavelength of 1557.80 nm and a spectral line-width of ~ 5.4 nm. The bound soliton pulses have a stronger spectral modulation with a fixed separation of 4.03 nm.4. Using the erbium-ytterbium co-doped fiber amplifier, the multistability states have been amplified. The amplified CTL has a tuning range from 1544.70nm to 1558.00nm, the side-mode suppression ratio of more than 35 dB and the 3-dB spectral less than 0.1nm. The light-to-light efficiency of the laser is about 10%.The amplified mode-locked and the bound solitions have also been realized.