High-intensity vortex beams with tunable topological charges and low coherence are highly demanded in applications such as inertial confinement fusion (ICF) and optical communication. However, traditional optical vortices featuring nonuniform intensity distributions are dramatically restricted in application scenarios that require a high-intensity vortex beam owing to their ineffective amplification resulting from the intensity-dependent nonlinear effect. Here, a low-coherence perfect vortex beam (PVB) with a topological charge as high as 140 is realized based on the super-pixel wavefront-shaping technique. More importantly, a globally adaptive feedback algorithm (GAFA) is proposed to efficiently suppress the original intensity fluctuation and achieve a flat-top PVB with dramatically reduced beam speckle contrast. The GAFA-based flat-top PVB generation method can pave the way for high-intensity vortex beam generation, which is crucial for potential applications in ICF, laser processing, optical communication and optical trapping.

基于几何稳相法求解调制相位，使用傅里叶透镜进行傅里叶变换，在后焦面处聚焦，得到对应的平顶光束，从而将圆形高斯光束整形为方形平顶光束，其中光路参数对整形质量将产生较大影响。实验中发现，方形平顶光束受零级光影响均匀性较差，因此详细分析了零级光产生的原因，提出了有效的解决方法，并对实验结果中出现的零级光通过叠加闪耀光栅直接移除。实验结果表明：移除零级光后方形平顶光束的能量利用率为72.3%，光束均匀性高达97.2%，优于传统整形方法。最后进一步分析了全息图与入射光束偏移量、离焦以及入射光束束腰半径对几何稳相法整形质量的影响，为几何法光束整形的应用提供了便利。

高强度辐射场构建系统是对多种**进行电磁辐照效应试验的关键装备，其要求在距天线一定距离的区域内产生高强度且尽量均匀分布的电磁场。本文设计了一款适用于该系统的X波段偏置卡塞格伦多模反射面天线。用反射面天线是为了获得尽可能高的增益，使期望区域内的场强尽可能大；用多模反射面理论实现了窄波束的平顶赋形，使期望区域内的场趋于均匀分布，区域外的场迅速减小。实测结果表明天线增益大于29.8 dB，3 dB波束宽度不小于4.6°，在此范围内方向图幅度起伏小于2 dB，平顶特性明显。此外，偏置的反射面天线还有馈源遮挡小、馈线损耗低和易于折叠收藏等优点，可以很好的应用于电磁环境模拟试验设备中。