Zhang Shuyan, Yang Qiguang, Lüpke Gunter
Department of Applied Science, The College of William and Mary, Williamsburg, Virginia 23187, USA.
Appl Opt. 2005 Sep 20;44(27):5818-23. doi: 10.1364/ao.44.005818.
We studied the spatial intensity profile of an ultrashort laser pulse passing through a laser beam shaping system, which uses diffractive optical elements to reshape a Gaussian beam profile into a flat-topped distribution. Both dispersion and nonlinear self-phase modulation are included in the theoretical model. Our calculation shows that this system works well for ultrashort pulses (approximately 100 fs) when the pulse peak intensity is less than 5 x 10(11) W/cm2. Experimental results are presented for 136 fs pulses at 800 nm wavelength from a Ti:sapphire laser with a 6 nJ pulse energy. We also studied the effects of lateral misalignment, beam-size deviation, and defocusing on the energy fluence profile.
我们研究了超短激光脉冲通过激光束整形系统时的空间强度分布，该系统使用衍射光学元件将高斯光束分布重塑为平顶分布。理论模型中同时考虑了色散和非线性自相位调制。我们的计算表明，当脉冲峰值强度小于5×10¹¹W/cm²时，该系统对超短脉冲（约100飞秒）效果良好。给出了来自钛宝石激光器、波长800纳米、脉冲能量6纳焦、脉宽136飞秒的脉冲的实验结果。我们还研究了横向失准、光束尺寸偏差和离焦对能量注量分布的影响。
