以Cr:YAG作为饱和吸收体,利用α向切割的Nd:GdV04晶体的自受激拉曼散射效应,实现了结构紧凑的1173nm拉曼激光器的调Q锁模输出。Nd:GdV04晶体长度为10mm,Nda+离子掺杂浓度为0.2%;Gr:YAG晶体的初始透过率为70%。激光器为LD端面泵浦,折叠腔结构,并且采用了透过率为10%的输出镜。泵浦功率5w时激光开始振荡输出。锁模脉冲重复频率高达900MHz;在最高泵浦功率时,1173nm激光平均输出功率为180mw,调Q包络宽度为11ns。同时,利用10mm长的I类匹配LBO作倍频晶体,成功实现了锁模黄光的输出,输出平均功率为10mw。并对586.5nm脉冲黄光的光谱进行了测量。激光器设计合理,热效应对激光器的影响被有效抑制。
A compact diode-pumped passively Q-switched and mode-locked 1 173 nm Nd: GdVO4 self-Raman laser has been demonstrated. Frequency shifting is generated by stimulated Raman scattering of Nd: GdVO4 laser material. An effident Cr:YAG crystal is used as the saturable absorber. The Nd3+ concen- tration of the Nd:GdVO4 crystal is 0. 2 at. % ,and its length is 10 mm. The initial transmission of Cr: YAG at 1063 nm is 70%. A folded laser cavity with three mirrors and an output couple with 10% transmittance are designed in the diode end-pumped laser. The oscillation threshold of the 1 173 nm first Stokes is about 5 W. The repetition rate of the mode-locked pulse train is 900 MHz. At the maximum incident pump power,the average output powr is 180 mW and the Q-switched envelope duration is about 11 ns. The mode-locked yellow laser outptu is also realized by use of LBO frequency-doubling crystal. The LBO crystal is cut for the type I critical phase matching and its length is 10 mm. The average output power of yellow laser is about 10 mW. The spectrum of the 586.5 nm yellow laser is also detected. The laser is better designed and the thermal lens effect does not affect the laser oscillation seriously.