Cover Story：Liu X -Q, Bai B -F, Chen Q -D, Sun H -B. Etching-assisted femtosecond laser modification of hard materials. Opto-Electron Adv 2, 190021 (2019).

This review introduces the recent development in the field of high precision and high efficiency micro/nanofabrication of hard materials by etching-assisted femtosecond laser modification from the fundamental to their applications, including areas of micro-optics, micro-electronics, micro-mechanics and microfluidics.
The research group of Prof. Hong-Bo Sun from Tsinghua University introduce the development of etching-assisted femtosecond laser modification for processing of hard materials in this review. Due to the properties of high hardness, high thermal stability, chemical inertness, and excellent photoelectric performances, hard materials (such as diamond, sapphire, silicon carbide, etc.) become the ideal materials for fabrication of micro/nano devices which is used for working under harsh conditions, such as high radiation, high temperature, and corrosion environment.