High-contrast front end based on Yb: YAG solid-state laser for PW-level Ti: sapphire laser.

In this paper, we demonstrate a high-contrast front-end laser system based on Yb: YAG solid-state laser for Ti: sapphire terminal amplification. An ultrafast Yb: YAG solid-state laser is used to generate a broad-spectrum seed through white light generation (WLG), and then the signal light near 1600 nm is amplified by three-level colinear optical parametric chirped pulse amplification (OPCPA). Finally, a fs second harmonic generation (SHG) is used to obtain a laser output with a central wavelength of 795 nm, a pulse width of 40.2 fs, a contrast baseline of nearly 10^-12 within 1 ns, and almost no ps pedestal. We used this laser system as a seed to amplify it to about the theoretical estimated 30 TW level, showing good dispersion properties and contrast preservation capabilities.