Advances in fabrication of micro-optical components by femtosecond laser with etching technology.

• Advances in femtosecond laser with etching fabrication of micro-optical components are reviewed. • Wet and dry etching processes for various hard materials are described. • Cutting-edge applications of femtosecond laser with etching are introduced. • Current challenges and future perspective of this field have been discussed. With advantages of small size, light weight, flexible design, and easy mass production, micro-optical components of hard materials have a wide range of potential applications in artificial intelligence, information processing, aerospace, biomedicine, laser technology, etc. However, it is difficult to realize three-dimensional (3D) micro-optical components with complex morphologies. In recent years, femtosecond laser with etching technology has proven to be effective for the fabrication of micro-optical components in hard materials owing to their high precision, high surface quality, and ability to fabricate arbitrary 3D structures. This review focuses on the recent advancements in femtosecond laser with etching fabrication of micro-optical components of various materials. We briefly introduce femtosecond laser modification and summarize the wet and dry etching processes of various materials. According to the types of optical components, the methods and applications of optical components fabricated by femtosecond laser with etching are discussed. The paper concludes with a follow-up and an outlook of femtosecond laser processing in femtosecond laser with etching fabrication of micro-optical components. [ABSTRACT FROM AUTHOR]