Dispersive Temporal Interferometry toward Single‐Shot Probing Ultrashort Time Signal with Attosecond Resolution

With the intensive research on ultrafast dynamics in physics and chemistry, the single-shot measurement of ultrashort time change has become increasingly important. The most advanced oscilloscope with the time-lens technique possesses subpicosecond resolution, while the interferometer can single-shot probe time event within one optical cycle. However, the single-shot measurement of time difference beyond optical cycle but less than time-lens' resolution is still inaccessible. Herein, a technique, the dispersive temporal interferometer (DTI), to break through the gap between interferometer and time lens on single-shot time measurement, is reported. The concept is an analogy to the spatial interference: a pulse passes two paths to assemble into a pulse pair, and temporal interference arises after large dispersion, which can single-shot record the imposed time change. Experimentally, it is measured that its resolution is sub-20 as (0.004 optical cycle) over a range of larger than 2 ps (400 optical cycle), with a range-to-resolution ratio of 10(5) and sampling rate of 42.8 MHz. Moreover, a DTI-based gyroscope with sensitivity of 348 as/(deg s(-1)) is fabricated to demonstrate its applications in optical sensors. This technique can precisely single-shot monitor ultrashort time change in attosecond resolution and has a prosperous application prospect in capturing ultrafast process.