Independent and parallel 3D scanning method based on holographically shifted femtosecond multi-foci

Combining spatial light modulation with femtosecond laser two-photon lithography can effectively promote the development of micro/nano additive manufacturing technology. As a typical technology, holographical parallel multi-foci can improve processing efficiency, but it is limited for fabricating periodic array structures with consistent morphology. In this Letter, femtosecond multi-foci are generated to independently fabricate micro-structures with distinct features and microlens arrays with varying radii. This is accomplished by pre-designing holograms, combining lens phase and grayscale modulation, without the need for any moving equipment. By simultaneously achieving high resolution and throughput, we overcome the limitations of previous multi-foci processing, providing greater versatility while also reducing processing steps to enhance manufacturing consistency. This scanning strategy can significantly enhance the flexibility of two-photon lithography.