Combining high energy (>1 kJ) picosecond pulsed lasers with high energy (10 kJ~100kJ) nanosecond pulsed laser systems provides innovative tools for cutting-edge research in high-energy-density physics. This report introduces a high stable hybrid frontend design applied to a kilojoule picosecond petawatt laser facility. Adopting a hybrid approach of optical parametric chirped pulse amplification (OPCPA) and chirped pulse amplification (CPA), it achieves three chirped pulses outputs with a repetition of 1 Hz, single-pulse energy ³150 mJ, spectral bandwidth³5 nm, and pulse duration ³3 ns. The beam near-field modulation is better than 1.4, and the inter-beam delay (i.e. target arrival time) is continuously adjustable from 0 ns to 50 ns, supporting front-end seed injection for three-beam kilojoule picosecond petawatt laser facilities with high synchronous output. Temporal compression tests were performed on the amplified pulses, yielding a compressed pulse width of 580 fs, approaching the Fourier-transform limit. Further detailed analysis was conducted on the impact of parametric fluorescence and amplified spontaneous emission on the temporal contrast of the pulses.
 

kilojoule picosecond petawatt laser facility; frontend design; Fourier-transform limit