  Time-resolved electronic processes on the attosecond scale have recently
become experimentally accessible through the development of laser-based
pump-probe interrogation techniques such as the attosecond streak camera, the
reconstruction of attosecond beating by interference of two-photon transitions,
and the attoclock. In this work, we demonstrate that by combining the concepts
of the attosecond streak camera and the attoclock, time resolved processes down
to the time scale of tens of zeptoseconds come into reach. Key to advancing to
this remarkable level of time precision by this method termed the zeptosecond
angular streak camera (ZASC) is its substantial intrinsic time-information
redundancy. The ZASC results in a remarkably simple streaking trace, which is
largely independent of the precise temporal structure of the streaking pulse,
thereby bypassing the need for detailed characterization of the streaking
field. Moreover, it is capable of retrieving information on the duration of the
pump pulse. It is also capable of reaching attosecond-level precision in a
single-shot mode that may be useful for free-electron-laser experiments. This
concept promises to open pathways towards the chronoscopy of zeptosecond-level
ultrafast processes.
