Validation of the direct-drive approach to inertial confinement fusion
requires the development of a 351-nm wavelength, 30-kJ, 50-TW laser s
ystem with flexible pulse shaping and irradiation uniformity approachi
ng 1 %. An upgrade of the existing OMEGA direct-drive facility at Roch
ester is planned to meet these objectives. In this article, we review
the design rationale and specifications of the OMEGA Upgrade laser wit
h particular emphasis on techniques planned to achieve the required de
gree of beam smoothing, temporal pulse shape, and beam-to-beam power b
alance.