Research on the joint design of continuous phase plate and lens array for beam smoothing

High-power laser systems have high requirements on the size, shape, and uniformity of the focal spot. Both continuous phase plate (CPP) and lens array (LA) can be used for beam shaping and smoothing. However, their ability is limited and there are few studies on the cooperation of CPP and LA. In this paper, the joint design of the CPP and LA was proposed, we theoretically analyzed its principle and studied the method to achieve better shaping and smoothing performance. Then, the far-field focal spot properties of three beam smoothing methods of the LA, the CPP, the CPP combined with the LA were obtained and compared through numerical simulation. The result shows that the LA is mainly contribution to shaping and the CPP mainly reduces the high-contrast intensity modulation to a certain extent. The joint design of the CPP and the LA greatly improves the uniformity of the far-field focal spot, which is valuable for expanding the application scope of the CPP and the LA.