Frequency doubling of multi-terawatt picosecond pulses

The frequency-doubling efficiency and resultant focal spot quality of a lar ge aperture (140 x 89 mm) subpicosecond, chirped pulse amplified (CPA) 1054 -nm beam for laser-matter interaction studies has been investigated using t he Vulcan Nd:glass laser system (Danson et al. 1998). The effect of B-integ ral on the CPA beam quality was studied and is shown not to be the dominant cause of the observed frequency-doubled beam break-up. Conversion efficien cy tests were carried out on small aperture KDP (type I) crystals at a rang e of incident intensities up to 3 x 10(11) W/cm(2) giving the optimum cryst al thickness for pulses in the 0.3-3 ps region. A large-aperture frequency- doubled beam was commissioned and delivered pulses of over 10 TW onto targe t for an electron acceleration experiment.