Improved uniformity of target irradiation by combining an orthogonal cylindrical lens array and the polarization control

Abstract

A scheme of combining technology of orthogonal cylindrical lens array (OCLA) and polarization control plate (PCP) is introduced to improve target irradiation uniformity in laser fusion. The feasibility of the scheme is also analyzed by detailed two-dimensional simulation. It shows that a focal pattern with flat-top and sharp-edge profile could be obtained with an OCLA, while interference stripes inside the pattern are smoothed out by the use of the polarization control plate (PCP) technique. Moving the target slightly from the exact focal plane of the principal focusing lens can eliminate middle-scale-length intensity fluctuation further. And a well-irradiated laser spot with small nonuniformity and great energy efficiency can be obtained in this scheme.