Research On All-solid-state Passively Q-switched Yellow-green Laser

All-solid-state laser(Laser Diode Pumped Solid-state Laser or DPSSL) refers to using the laser diode(LD) as pump source for solid-state laser which is an important branch of laser technology. All-solid-state laser has high conversion efficiency, simple structure, high reliability, good beam quality and long life and other advantages. All-solid-state laser can realize continuous and adjustable Q-switched operation. All-solid-state passively Q-switched laser can obtain narrow pulse width and high peak power and has the advantages of compact structure and low cost. The main research work of this paper is:This paper discusses the main principle of the optical frequency doubling technology and passive Q-switched technology, introduces the level structure of Cr:4+YAG crystal and passively Q-switched mechanism. The paper analyzes the structure of energy level of Nd:YAG crystal, discusses the method of obtained 1123 nm line oscillation. All-solid-state continuous 561 nm laser is designed, the 1064 nm and 1318 nm line is restrained by designing the reasonable coating of cavity and then obtained a stable single line 561 nm laser output by using the birefringent filter and the etalon to suppress 1112 nm and1116nm line. we obtain 227 mW and 254 m W 561 nm single line output at the pump power of 4.8W respectively, the optical to optical conversion efficiency is 4.73% and 5.29% respectively. We conclude that the loss of resonator caused by etalon is smaller than the birefringent filter, so using the etalon can obtain a higher output, while the birefringent filter can be more effective to suppress the line width of output.In addition, passively Q-switched 561 nm laser is designed. The Cr4+: YAG crystal is used as Q-switched crystal and loss selective optical element, the 561 nm single line pulse output is obtained. The output power is 124 mW, pulse frequency repetition is 18.21 kHz, pulse width is 71 ns at the LD pump power of 4.8W, the peak power is 95 W.