Advanced laser pulse metrology through 2D self-referenced spectral interferometry.

The temporal contrast requirements of high-power laser pulses are growing with the ongoing increase of available intensities. Novel measurement concepts in the far-field domain capable of providing information on the origin of pre-pulses or coherent and incoherent pedestals are thus needed with single-shot and full-spectral band measurement capabilities. Advancements of the 2D self-referenced spectral interferometry (SRSI) method represent one solution to this need. Here, we discuss experimental progress together with the theoretical potential and limitations of this approach. The dynamic characteristics of measurements in single-shot-mode and through accumulation of shots is used to measure coherent and incoherent temporal contrast features on dynamic levels of up to 90 dB and a temporal range of up to 100 ps and with 25 fs resolution. This unprecedented performance is validated through the measurement of coherent pre-pulses below the incoherent amplified spontaneous emission (ASE) level and the determination of their spectrograms.