Chinese Optics Letters (COL) invites high quality articles for a Special Issue on Ultrafast Optics: fundamentals and applications to be published in Oct. 2022. Ultrafast laser science and technology have profoundly affected our understanding of nature and our ability to transform the world. By concentrating the light energy into picosecond (10^-12 s), femtosecond (10^-15 s) and even attosecond (10^-18 s) time scale, ultrashort intense laser pulse can be used to change material properties or visualize ultrafast dynamics. This issue is related to the generation of ultrashort laser source and its applications in light-matter interaction and to the related imaging or detection techniques.