The ultrafast dynamics of electron behavior encapsulates comprehensive information regarding non-equilibrium states and microscopic energy exchanges. It serves as a crucial microscopic lens for understanding the intricate interplay between light and matter at extreme spacetime scales. To decode this process, methodologies such as attosecond streaking spectroscopy and RABBITT (Reconstruction of Attosecond Beating by Interference of Two-photon Transitions), both rooted in the pump-probe technique, have emerged as pivotal tools for scrutinizing electron motion within atoms and molecules.

Nevertheless, as an indirect measurement approach, the pump-probe method hinges on external timing references. Its theoretical underpinning relies on the energy spectrum aliasing that occurs during strong-field emission processes. Consequently, the temporal information pertaining to electron emission becomes obscured within the energy spectrum, complicating the direct establishment of a correlation between energy and time. Hence, there exists a pressing demand for the development of a technique capable of directly mapping energy to the corresponding emission time.