Full diagnostics and optimization of time resolution for time- and angle-resolved photoemission spectroscopy

Achieving a high time resolution is highly desirable for revealing the electron dynamics and light-induced phenomena in time- and angle-resolved photoemission spectroscopy (TrARPES). Here, we identify key factors for achieving the optimum time resolution, including laser bandwidth and optical component induced chirp. A full diagnostic scheme is constructed to characterize the pulse duration and chirp of the fundamental beam, second harmonic, and fourth harmonic, and prism pairs are used to compensate for the chirp. Moreover, by using a Sb2Te3 film as a test sample, we can achieve a high test efficiency for the time resolution during the optimization process. An optimized time resolution of 81 fs is achieved in our TrARPES system with a high repetition rate tunable from 76 to 4.75/n MHz. Published under license by AIP Publishing.

Automated summary

Achieving high time resolution in TrARPES system requires consideration of key factors such as laser bandwidth and optical component-induced chirp. By using a test sample and appropriate compensation methods, a high time resolution can be achieved.