Diffractive Elements Developed for Uniform Illumination in Inertial Confinement Fusion

In inertial confinement fusion(ICF) experimental researches, especially in direct drive ICF experimental researches, energy of the incident high power laser beam must be focused onto the target surface very uniformly. To achieve high illumination uniformity for target, several techniques have been developed, such as random phase plate (PR)[1], induced spatial incoherence (ISI)[2], smoothing by spectral dispersion (SSD)[3], lenslet array (LA)[4], etc.. Although these techniques have proven valuable in ICF applications, all of them have some limitations and can't meet all of the requirements of the applications.