A laser beam delivery system for transforming a laser energy profile into
a desired laser beam output energy profile. The laser beam delivery
system comprises a laser for generating a laser beam along a beam path,
at least one extra-cavity harmonic generation element being located along
the beam path for generating harmonic multiples of a beam input
frequency, and an extra-cavity beam expansion element, located before the
at least one harmonic generation element, for expanding and collimating
the laser beam prior to the laser beam being multiplied by the at least
one harmonic generation element. The beam expansion element may be a
refractive lens.