Investigation Of Passively Q-switched Solid-state Lasers Based On Nd:GAGG And Gold Nano-materials Around 1?m

Diode-pumped passively Q-switched laser has wide applications in the fields such as laser telecommunication,laser radar,non-linear transformation and laser medical due to its advantages such as small volume,compact structure and low cost and so on.The lasers around 1 ?m are playing an important role in their fields.For example,1064 nm laser is the most commonly used in laser research,at the same time,it can be used in laser surgery and material processing.1.1 ?m laser can be applied in selective photo-ionization in laser chemistry and used as a pump source for thulium up-conversion fiber lasers to generate blue laser emission.In addition,a 0.55 ?m frequency doubling yellow laser has many important applications in laser display,atmospheric remote sensing,medical treatment and laser precision manufacture.Gold nano-material as the representative of the two-dimensional nano material has become the focus of attention of researchers.Because of the surface plasmon resonances,its unique optical properties are related to its size and shape.By adjusting its size,the gold nano-material's absorption peak can be changing from visible to near infrared.The emphasis of this thesis is the characteristics of passively Q-switched laser with Nd:GAGG and gold nano-materials saturable absorber around 1?m.We use the Nd:GAGG,Nd:YAG ceramics and Nd:YVO4 as the laser crystal,the Cr4+:YAG,GNRs and GNTs as the saturable absorber.With the pump of semiconductor laser,we obtained lasers operating at 1106,1123 and 1064 nm.The main work includes the following:1.We study the recent development of the passively Q-switched lasers.At the same time,we introduce the properties and application of the Nd:GAGG,Nd:YAG,Nd:YVO4,Cr4+:YAG,GNRs and GNTs.2.We use Cr4+:YAG as saturable absorber in diode-pumped passively Q-switched Nd:GAGG 1106 nm laser.The maximum average output power is 0.35 W with the shortest pulse width of 26.2 ns,and the pulse repetition frequency is 10 kHz.3.We demonstrated the fabrication and the optical properties of the GNRs.Then we get the 1123 nm laser by using the Nd:YAG ceramics and GNRs for the first time.The maximum output power,pulse repetition frequency and the shortest pulse width are 163 mW,120 kHz and 566 ns.4.We demonstrated the fabrication and the optical properties of the GNTs.By using the Nd:YVO4 as the gain medium,GNTs as the saturable absorber,we get the maximum output 218 mW at 1064 nm.The shortest pulse width is 165 ns and the maximum pulse repetition frequency is 300 kHz.