Abstract: The 2023 Nobel Prize in Physics was awarded to Pierre AGOSTINI of the Ohio state university, Ferenc KRAUSZ of Max Planck institute of quantum optic, and Anne L'HUILLIER of Lund university for their experimental methods in generatingatto second pulses of light for the study of electron dynamics in matter. They experimentally produced high-order harmonics, attosecond pulse trains, and isolated attosecond pulses, laying the foundation for attosecond physics. The generation and applications of high-order harmonics and attosecond pulses in strong-field ultrafast optics were elaborated, along with an outlook on the opportunities and challenges in ultrafast detection processes.