Ultra-high precision laser nanoprinting based on defect compensated digital holography for fast fabricating optical metalenses

• KAIWEN JIE, ZHUOFAN YAO, YIYIN ZHENG, MINGHUI WANG, DIEFENG YUAN, ZEDA LIN, SHANTONG CHEN, Fei Qin, HUASE OU, Xiangping Li, and Yao-Yu Cao
• received 03/18/2024; accepted 05/14/2024; posted 05/15/2024; Doc. ID 522575
• Abstract: 3D structured light field manipulated by digital-micromirror-device(DMD)-based digital hologram has demonstrated its superiority in fast fabricating stereo nanostructures. However, this technique intrinsically suffers from defects of light intensity in generating modulated focal spots, which prevents from achieving high-precision micro/nanodevices. In this paper, we have demonstrated a compensation approach based on adapting spatial voxel density for fabricating optical metalenses with ultra-high precision. The modulated focal spot experiences intensity fluctuations of up to 3% with changing the spatial position, leading to a 20% variation of the structural dimension in fabrication. By altering the voxel density to improve the uniformity of laser cumulative exposure dosage over the fabrication region, we achieved an increased dimensional uniformity from 94.4% to 97.64% in fabricated pillars. This approach enables fast fabrication of metalenses capable of sub-diffraction focusing of 0.44λ/NA with the increased mainlobe-sidelobe ratio from 1:0.34 to 1:0.14. A 6x5 supercritical lens array is fabricated within 2 minutes, paving a way for the fast fabrication of large-scale photonic devices.