Study On LD Side-pumped All-solid-state 266nm Ultraviolet Laser

LD-pumped all-solid-state UV lasers have a wide range of applications in the industrial, medical and scientific research, so the international community has done a substantial amount of the research. In this paper, theoretical and experimental research of LD-pumped 266 nm all-solid-state ultraviolet laser were presented in the dissertation, the main subjects are as follows:1. The UV laser's developmental history is reviewed, and its advantages, main applications, research progresses and developing trends are introduced and summarized.2. The basic structure and principle of LD-pumped all solid state lasers are discussed through analyzing the characteristics of Nd:YAG ,the laser's cavity technology and its pumping structures. With comparison of the advantages and disadvantages for the different cavity structures, the plane-concave straight cavity include thermal lens is analyzed. Deriving from the rate equations, the analytic expressions of laser output power, threshold power and slope-efficiency of the laser are obtained.3. From the nonlinear effects of the interaction between optical media and light field, the theory of second-harmonic generation is analyzed. On the basis, phase-matching technology is studied and discussed. The characteristics of common crystals for SHG and FOHG are summarized. LD side-pumped 532nm A-0 Q-switched solid-state Nd:YAG laser is carried out on the basis of the theoretical research and numerical analysis. In the pumping current of 53 A and Q-switched repetition frequency of 22.4 kHz, the 532nm laser maximum average output power of 110W is achieved with a pulse width of 201ns and the largest single pulse energy of 4.9 mJ, corresponding to a peak power of 24.4 kW and doubling frequency efficiency of 60.4%.4. LD side-pumped 266nm solid-state Nd:YAG laser is carried out on the basis of the theoretical analysis. In the pumping current of 110 A, Q-switched repetition frequency of 22 Hz, voltage of 2890 V, and the maximum average output power of 480 mW at 532nm, the 266 nm UV laser maximum average output power of 53 mW is achieved with a pulse width of 20 ns and the largest single pulse energy of 2.4 mJ, corresponding to a peak power of 120 kW and green - UV conversion efficiency of 11%.The experimental results are analyzed in detail, which are in line with the theoretical and expected results.5. The last part is the summarization and suggestion of the dissertation.