Spatial light modulation for femtosecond laser manufacturing: Current developments and challenges

Since the invention of lasers, spatial-light-modulated laser processing has become a powerful tool for various applications. It enables multidimensional and dynamic modulation of the laser beam, which significantly improves the processing efficiency, accuracy, and flexibility, and presents wider prospects over traditional mechanical technologies for machining three-dimensional, hard, brittle, or transparent materials. In this review, we introduce: (1) The role of spatial light modulation technology in the development of femtosecond laser manufacturing; (2) the structured light generated by spatial light modulation and its generation methods; and (3) representative applications of spatial-light-modulated femtosecond laser manufacturing, including aberration correction, parallel processing, focal field engineering, and polarization control. Finally, we summarize the present challenges in the field and possible future research.