Based On The High Stability Of The Arr Energy Passively Q-switched And Mode-locked Laser

For the first time an anti-resonant ring (ARR) being introduced to a conventional passively Q-switched laser, the high stability and large energy single Q-switched pulses were obtained. Using an convex-ARR unstable resonator structure, passively mode-locking by utilizing BDN dye film with relaxation time of ground state in nanosecond magnitude was realized. Analysis by using the computer simulation with other theories verified the accuracy and reliability of the experiment results. The thesis was divided into four chapters as following:Chapter 1: Summarize the research background of the thesis, the significance of the selected topic as well as the major contents of the thesis and the achievements gained.Chapter 2: By analyzing the optical symmetry of ARR, the author showed the ARR configuration which was used in the research. The grating effect of ARR was analyzed and the theoretical analysis demonstrated that ARR was equivalent to a flat totally reflecting mirror.Chapter 3: ARR was introduced to a passively Q-switched laser. Cr4+:YAG crystal, BDN dye film and LiF : F2- color center crystal were selected as saturable absorber and the high stability and large energy single Q-switched pulses were obtained. The quality of output laser in this type laser was superior to that of conventional passively Q-switched laser. The experimental results were verified by using computer simulation through the rate equations of passively Q-switched laser. The experimental phenomena were reasonably explained by the grating effect of ARR and the variation of saturable absorber absorptivity before and after saturation with different initial transmissivity. To further verify the reliability of the theoretical analysis and experimental results, a lot of comparison experiments with LiF: F2-color center crystal in various parameters were conducted. The outcome further demonstrated the accuracy of the theoretical analysis and the reliability of the experimental results.Chapter 4: By analyzing energy level structure of BDN dye film in combination with rate equations, the authors pointed out the possibility of realizing passive mode-locking by using BDN dye film with relaxation time of ground state in nanosecond magnitude. In pulsed laser of convex-ARR unstable resonator structure, the stable mode-locked output was obtained, which testified the correction of the theoretical analysis.