啁啾脉冲激光放大系统中的色散研究

Research on the Dispersion of CPA Laser System

理论分析了飞秒钛蓝宝石激光啁啾脉冲放大系统中各光学元件引入的色散,讨论了以块状玻璃作为展宽器,以双棱镜对作为压缩器的应用,并以重火石玻璃ZF7为基材,模拟了展宽——放大——压缩过程中脉冲宽度的变化。相较于光栅对展宽器来说,光学玻璃的展宽倍数较小,但是对于放大能量不高的预放大系统来说,这种展宽——压缩方式价格低廉、调节简便,具有较大的应用价值。通过灵活的选择基底玻璃材料及调节棱镜的插入量,或者将该展宽——压缩系统与光栅对及高阶色散啁啾镜混合使用,实现优势互补,可以进一步补偿高阶色散,缩短压缩脉冲宽度。

The role of dispersion in femtosecond Ti ： sapphire CPA system is theoretically analyzed. Based on the analysis, we simulate the stretch-recompress process with glass stretcher and double-prisms pairs compressor, which supply an optimized guide in the construction of CPA laser system. Compared to the grate stretcher, the positive dispersion of glass is less, but for pre-amplifier, the glass stretcher is more economical and with better maneuverability. Choosing appropriate glass material and changing the inserted length of prism pairs, or further adding grate pairs and chirped mirrors, the high order dispersion could be compensated and the pulse width compressed shorter.