An investigation was made of a laser (Nd:YLF/Nd glass) laser system ge
nerating pulses of 1.5 ps duration and up to 0.4 TW power at the 1053
nm wavelength. Chirped pulse amplification in a multipass amplifier wa
s used. The amplifier had a misaligned conjugate cavity and a net gain
of similar to 4 X 10(6), as well as two additional amplifiers with an
output aperture 20 mm in diameter. After optimisation of the paramete
rs of this multipass amplifier the angular divergence of the output ra
diation was close to the diffraction limit and the average intensity w
as up to similar to 10(17) W cm(-2) in a focused beam. This laser syst
em was developed as the front-end component of a multiterawatt laser f
acility under construction for research on the interaction of ultrastr
ong fields with matter.