根据?ffner展宽器的原理和设计,进行了光学参量啁啾脉冲放大系统中信号光脉冲展宽的实验研究.通过数值方法,合理地选择了展宽器光学元件的各项参数,即光栅常数为1 800 (102 mm×102 mm),凹面镜曲率半径为1 000 mm,凸面镜与凹面镜之间的距离为653 mm,信号光入射角为51.05°.实验结果表明,优化后的?ffner展宽器可以将脉宽为30 fs的信号光脉冲展宽到545 ps, 展宽比为18 167,满足OPCPA放大的需要.

According to the design and the principle of the ?ffner stretcher, the pulse stretcher for OPCPA laser system was experimentally investigated. Using the numerical method, the four key parameters were appropriately selected, that is the angle of incidence being 51.05°, the distance from grating to concave spherical mirror being 653 mm, the curvature radius of the concave spherical mirror being 1 000 mm and the grating constant being 1 800 lines/mm. The experimental results demonstrate that an expansion of 30 fs to 545 ps pulse and a stretching ratio of 18,167 can be obtained by adjusting the key parameters.