啁啾脉冲的光谱整形

Spectrum Shaping of Chirped Pulse

为了获得更高功率的输出激光脉冲,需要将注入到主放大链的种子脉冲进行光谱整形来补偿放大过程中的增益窄化效应。利用展宽器中啁啾脉冲的光谱具有空间排布的特点,采用石英晶体平凸透镜空间光强度调制器间接地实现窄带激光脉冲的光谱整形,在展宽器的输出端获得了光谱呈平顶分布的种子啁啾脉冲。通过调节偏振片的透偏方向,可方便地调谐输出脉冲光谱的形状。

In order to obtain a higher power laser pulse in the terminal, it is necessary to conduct spectrum shaping before the seed pulse being injected into the main amplifier chain to compensate the effect of gain narrowing. Based on the spatial distribution of the chirped pulse spectrum in the stretcher, a scheme to shape the spectrum of a narrowband laser pulse by using a quartz crystal piano-convex lens spatial light modulator is proposed. The flat-topped spectrum is obtained at the output of the stretcher. The spectrum profile can be easily switched from one profile to another by regulating the polarizing direction of the polarizer.