We demonstrate the design, fabrication, and experimental characterization of near-field binary phase transmission diffractive optical elements (DOEs) in single crystal diamond. Top-hat and arbitrary pattern DOE beam shapers were numerically optimized using an iterative Fourier transform algorithm (IFTA). Commercially available single crystal diamond plates (${{3}}\;{\rm{mm}} \times {{3}}\;{\rm{mm}} \times {0.3}\;{\rm{mm}}$) were patterned using hardmask deposition ($\alpha$-Si), e-beam lithography, and ${{\rm{O}}_2}$ plasma-based diamond reactive ion etching. The resulting binary phase relief patterns were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Experimental characterization of the single crystal diamond DOEs in transmission at $\lambda = 532\;{\rm{nm}}$ confirms excellent uniformity of the resulting top-hat beam profile as required in copper welding applications.

中文翻译：

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单晶金刚石中的衍射光学元件。

我们演示了单晶金刚石中近场二进制相位透射衍射光学元件（DOE）的设计，制造和实验特性。使用迭代傅里叶变换算法（IFTA）在数值上优化了礼帽式和任意图案DOE光束整形器。市售单晶金刚石板（$ {{3}} \; {\ rm {mm}} \倍{{3}} \; {\ rm {mm}} \倍{0.3} \; {\ rm {mm }} $）使用硬掩模沉积（$ \ alpha $ -Si），电子束光刻和$ {{\ rm {O}} _ 2} $基于等离子体的金刚石反应离子刻蚀。使用扫描电子显微镜（SEM）和原子力显微镜（AFM）对得到的二元相浮雕图形进行表征。对单晶金刚石DOE在$ \ lambda = 532 \; {\ rm {nm}} $时的传输进行实验表征，证实了所产生的礼帽光束分布具有极好的均匀性，这在铜焊接应用中是必需的。