Simulation of Patterns and Qualitative Analysis of Pattern Rotation in an End-Pumped Nd：YVO4 Laser

We simulate some laser output patterns observed in our previous experiment employing superposition of Laguerre- Gaussian modes. The rotating pattern is qualitatively analysed from the point of contemporary spatial burning hole effect of the lasing crystal.     

Mathematica软件在波动教学中的应用

利用数学软件Mathematica 7.0的动画与声音播放功能,将半波损失、驻波、拍等内容直观化显示,有效提高教学效果.     

基于MOPA结构的1120nm掺Yb光纤放大器

基于主振荡功率放大器,采用1120nm光纤激光器作为种子激光,将其注入20m大模场面积单模双包层掺Yb光纤放大器,并用976nm半导体激光器泵浦实现了1 120nm信号光输出.实验中将注入种子激光功率预设为10mW,当半导体激光器泵浦功率增大至1.5 W时,放大器系统开始输出1 120nm信号光.当泵浦功率低于3.4W时,信号光功率随泵浦功率缓慢增长,系统斜率效率较低;而当泵浦功率高于3.4W时,信号光功率随泵浦功率线性增长,斜率效率明显增大,达到48.5%.限于最大注入泵浦功率为6.8W,放大器输出最高1 120nm信号光功率为1.97W,总的光-光转化效率为29%.输出信号光中心波长为1 120.89nm,线宽为0.02nm,极好地保持了种子激光的特性.结合实验情况,利用双包层光纤放大器的稳态理论模型,采用有限差分方法模拟了放大器输出信号光功率随泵浦光功率的变化曲线,结果显示理论模拟所得变化趋势与实验结果吻合良好,系统将在泵浦功率达到200W左右时达到饱和状态,说明目前光纤放大器系统具有很大的功率提升空间.     

Diode-pumped passively Q-switched and mode-locked Nd:YLF laser with Cr~(4+):YAG saturable absorber

A diode-pumped passively Q-switched Nd:YLF laser was demonstrated by using saturable absorber of Cr4 :YAG. At the incident power of 7.74 W, pure passively Q-switched laser with per pulse energy of 210μJ and pulse width of 19.6 ns at repetition rate of 1.78 kHz was obtained by using Cr4 :YAG with initial transmission of 80%. At the incident power of 8.70 W, a Q-switched mode-locking with average output power of 650 mW was achieved, the overall slop efficiency was 16%, corresponding to the initial transmission of 85% of Cr4 :YAG.     

湍流大气中无衍射涡旋光束的展宽及相位奇点的演化

以经过圆形孔径截断的Bessel涡旋光束和Bessel-Gauss涡旋光束为例,数值模拟了近似无衍射涡旋光束在湍流大气中传输时引起的光束扩展和畸变光场中相位奇点的变化。仿真结果表明,与Bessel涡旋光束相比,Bessel-Gauss涡旋光束由大气湍流引起的束宽扩展较小,且在一定条件下其相位奇点代数和与入射涡旋光束的拓扑荷数保持一致;在远距离传输时,Bessel-Gauss涡旋光束相位奇点代数和的起伏偏差远小于Bessel涡旋光束。Bessel-Gauss涡旋光束在自由空间光通信中作为信息载体具有较大的优势。     

An efficient intracavity-pumped KTP optical parametric oscillator at 1572 nm

We demonstrate an efficient and eye-safe wavelength intracavity optical parametric oscillator (OPO), based on a KTP crystal inside a Q-switched Nd:YVO4 laser end pumped by a fiber-coupled diode laser. In the acousto-optic Q-switched operation with the pulse repetition rate of 10 kHz, a 1572-nm eye-safe laser with the average power of 237 mW at the incident pump power of 5.64 W is obtained. Under the pulse repetition rate of 5 kHz, the signal light with pulse width of 2 ns and peak power of 18.5 kW is achieved. The conversion efficiency of the average power is 4.2% from pump diode to OPO signal output and the signal pulse duration is about 13 times shorter than that of the depleted pump light.     

High power CW and Q-switched operation of a diode-side-pumped Nd:YAG 1319-nm laser

We demonstrated the highly efficient continuous wave(CW)and Q-switched infrared laser from a diode- side-pumped Nd:YAG crystal.A CW output as high as 66 W at 1319 nm was achieved under the pump power of 460 W,corresponding to a coversion efficiency of 14.3%.A maximum average power of 8.9 W of TEM_(00) mode was obtained in Q-switched operation at the repetition rate of 8 kHz.The performance of the laser considering the thermal lens effect induced by pump power was also analyzed.     

用粒子群算法校正三片镜系统的像差（特邀）

提出将粒子群算法用于三片镜光学系统的优化设计。设计了关于曲率半径、透镜面之间的距离、玻璃折射率、系统长度等光学系统结构参数的光学评价函数,用此函数作为粒子群算法中的适应度函数,实现了对光学系统的自动寻优。给出了用粒子群算法进行三片镜光学系统设计过程实例,结果证明：用粒子群算法可以设计出球差、子午场曲、子午光线弥散值都很小的三片镜光学系统;并且用该算法进行光学设计不需要知道系统具体的初始结构,克服了现有光学设计软件高度依赖具体初始结构的缺点,可以自由控制结构参数的搜索范围,从而提高光学系统设计的智能化程度。     

High power CW and diode-side-pumped Q-switched operation of a Nd：YAG 1319-nm laser

We demonstrated the highly efficient continuous wave （CW） and Q-switched infrared laser from a diode- side-pumped Nd：YAG crystal. A CW output as high as 66 W at 1319 nm was achieved under the pump power of 460 W, corresponding to a coversion efficiency of 14.3%. A maximum average power of 8.9 W of TEM00 mode was obtained in Q-switched operation at the repetition rate of 8 kHz. The performance of the laser considering the thermal lens effect induced by pump power was also analyzed.     

板条放大器同步泵浦的宽调谐MgO:PPLN中红外光参量振荡器（英）

搭建了Nd:YVO4/SESAM锁模激光器,采用LDA泵浦的Innoslab对其进行功率放大,最后同步泵浦MgO:PPLN实现了宽调谐皮秒中红外光参量运转。通过改变MgO:PPLN的温度和通道,实现了信号光1415~1557 nm、闲频光3362~4290 nm范围的宽调谐输出,其中最高的光光转换效率为17.5%。同步泵浦功率为16 W,脉冲重复频率为116.9 MHz时,同时获得1.33 W的1518 nm信号光和1.26 W的3558 nm闲频光输出。