The frequency-doubling efficiency and resultant
focal spot quality of a large aperture (140 × 89
mm) subpicosecond, chirped pulse amplified (CPA) 1054-nm
beam for laser–matter interaction studies has been
investigated using the Vulcan Nd:glass laser system (Danson
et al. 1998). The effect of B-integral 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 efficiency tests were carried out on small aperture
KDP (type 1) crystals at a range of incident intensities
up to 3 × 1011 W/cm2 giving
the optimum crystal 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 target
for an electron acceleration experiment.
Frequency doubling of multi-terawatt picosecond pulses