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

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 (SH) nanoparticles (NPs) and dispersion-scan (d-scan). Scattering adds an incoherent component to the d-scan trace and our retrieval procedure allows for correctly the trace. Comparison with a thin crystal (BBO, Beta Barium Borate) 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 ultrabroadband spectra at room temperature with standard spectrometers, in any spectral range.