Nano-dispersion-scan: measurement of sub-7-fs laser pulses using second-harmonic nanoparticles

Opt Lett. 2019 Oct 15;44(20):4921-4924. doi: 10.1364/OL.44.004921.

Abstract

We demonstrate the measurement and retrieval of sub-7-fs laser pulses from a broadband Ti:Sa oscillator using ensembles of commercially available second-harmonic nanoparticles (NPs) and dispersion scan (d-scan). Scattering adds an incoherent component to the d-scan trace, and our retrieval procedure allows for correctly weighting the coherent and incoherent contributions to the trace. Comparison with a thin crystal [beta barium borate (BBO)] gave consistent pulse durations (6.56±0.03 fs for BBO and 6.5±0.1 fs for the NPs). These results pave the way to using ensembles of NPs for the measurement of ultrashort light pulses with ultra-broadband spectra at room temperature with standard spectrometers, in any spectral range.