Today, the accurate characterization of ultra-broadband few-cycle laser pulses is crucial to investigate ultrafast dynamic processes, for example in the fields of nanophotonics and attosecond science. This type of lasers generate pulses with highly structured ultra-broadband spectra and sub-10-fs pulse durations. These unique spectral and temporal characteristics make them particularly attractive for ultrafast spectroscopy and microscopy. 

The ultrafast optics community has developed various methods to measure ultrashort laser pulses including FROG, SPIDER, MIIPs, amplitude swing or d-scan. The precise characterization of few-cycle laser pulses with the above-mentioned spectral and temporal features is particularly challenging when compared to measuring longer pulses with much narrower and Gaussian spectra.

In this work, we use the d-scan method combined with two dimensional flakes of WS_{2} to accurately measure ultra-broadband (650-1050 nm) few-cycle laser pulses. In particular, we use the atomically thin WS_{2} flakes to benefit from (1) their extremely large nonlinear response to attain second-harmonic generation and (2) their broad range of transparency. In addition to these features, their atomically thin geometry allows for attaining relaxed phase-matching conditions. We experimentally measure d-scan traces using monolayers and trilayers of WS_{2} as well as using a 10-µm-thick BBO crystal to record control measurements. We extract the temporal intensity distribution of the laser from the traces and find excellent agreement among the pulses obtained for all three different media. Our results suggest that it is possible to use other 2D materials to characterize few-cycle laser pulses in various spectral regions.