Diverse Optical Fabrication Technologies Used In the Nova KDP Arrays

Abstract

Crystal arrays are precision optical components consisting of a matrix arrangement of Individual Potassium Dihydrogen Phosphate (KDP) crystal segments mounted edge-to-edge and constrained between two windows In an Index fluid-filled housing. The arrays act as a single optical element. They are mounted at the output of the laser and must, as nearly as possible, simulate the performance of a non-matrixed assembly. To achieve this goal, we have employed state-of-the-art fabrication technologies such as single-point diamond machining of KDP, finite element modeling of optical distortions, flexure mounting of large (~ 1 meter diameter) fused silica windows, numerically-controlled diamond wire sawing, phase-scattering apodization, and gradient-index (sol-gel process) antireflectlve coating.