Study on the eight-pass single grating stretcher

In chirped pulse amplification system pulse stretching is an important part. To investigate the behavior of an eight-pass single grating pulse stretcher, we examine in two steps: firstly a unchirped ultrashort pulse goes first four-pass through the stretcher, it will be broadened in pulsewidth and provided with amount of positive chirps. Secondly this chirped pulse will has another four-pass experience through the stretcher. Followed by our close calculations, it is clear that stretching factor in the second part is almost 2, and the total stretching factor of this system is equal to the multiplication of the two factors.