用作飞秒脉冲展宽器的新型多膜光栅的设计

The design of a new multilayer blazed reflective grating used in broadening femtosecond lasers

采用薄膜光学技术,在传统反射式闪耀光栅的表面镀以多层薄膜以改善传统光栅的衍射特性和反射特性,用于控制展宽后脉冲的光谱强度分布,以及控制超短脉冲放大过程中的增益窄化效应。理论计算和实验表明,应用多膜反射式闪耀光栅作为展宽器件,种子脉冲的能量损耗小、展宽效率高,且放大过程中的增益窄化效应得到很好的补偿,另外,采用多膜反射式闪耀光栅还有方便实验调节,简化CPA系统,便于集成化的优点。

A new multilayer blazed reflective grating is shown，Using thin-film technology, the blazed reflective grating＇s diffraction property and reflectivity property have been improved greatly. Making use of these properties, the gain narrowing in femtosecond lasers is restrained. The calculation result and experiment result show that using this new grating to broaden seed pulse has many advantages： the loss of seed pulse energy is less, the efficiency of broadening is high，the gain narrowing is attenuated much， Furthermore it can make experiment easier and convenient for integration。