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

Abstract

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 105 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.