Study On LD Pumped High Power Green Pulse Laser

Diode laser (LD) pumped Q-switched green laser is researched widely. In my first part, it's main features, merits, and field of application as well as the present development at home and abroad is introduced.The work principle of all-solid-state laser is analyzed. Based on four-level system, the interaction theory between laser field and laser crystal is analyzed by the rate equation theory, then the character, such as threshold power, output power, slope efficiency etc., of solid-state laser are deduced. We also analyzed the double -frequency technique that applied universally in the field of solid-state laser and the effect of phase matching upon conversion efficiency.The theory of folded cavity is discussed. The stable condition of Z-shaped cavity A-O Q-switched system is analyzed by transmitted matrix. How the thermal focus length of laser crystal, the length of cavity, the curvature radius of output lens and such parameters of cavity affect the stability of the system is also analyzed in numerical way. The conclusion that shorter the cavity is, more stability the system is draw.In the following part, the characters of acoustic-optics Q-switching is analyzed. Q-switching technique is studied based on the Q-switching rate equation. And the optimum problem of Q_Switched lasers is also studied. We get the numerical result from the rate equation and analyze the relation between pulse energy, pulse power , pulse width and pump power. The output of the average power 1.345W and pulseenergy 67uJ was obtained in a one-end-pumped Z-shaped Nd:YVO4 laser under the condition that input power was 12.5W and frequency was 20kHz.The optic-optic transmit efficiency was 10.8%. In a two-end-pumped Z-shaped Nd:YVO4 laser, theoutput power was 4.7W and pulse energy was 134uJ when input power was 25.9Wand the frequency was 35kHz. The optic-optic transmit efficiency was 18.1%.Then the advantage and the different way of side-pumping was discussed here.And the optical and spectrum character of Nd:YAG crystal was study also. We design a side-pumped V-shaped cavity by the theory discussed in the former chapter .In the side-pumped A-O Q-switched intracavity doubled-frequency Nd:YAGgreen laser, the average output power 20W and pulse energy was obtained. The last part is the summarization and suggestion of the paper.