LAUSR

We demonstrate an on-chip, optoelectronic device capable of sampling arbitrary, low-energy, near-infrared waveforms under ambient conditions with sub-optical-cycle resolution. Our detector uses field-driven photoemission from resonant nanoantennas to create attosecond electron bursts that probe the electric field of weak optical waveforms. Using these devices, we sampled the electric fields of ~5 fJ (6.4 MV m−1), few-cycle, near-infrared waveforms using ~50 pJ (0.64 GV m−1) near-infrared driving pulses. Beyond sampling these weak optical waveforms, our measurements directly reveal the localized plasmonic dynamics of the emitting nanoantennas in situ. Applications include broadband time-domain spectroscopy of molecular fingerprints from the visible region through the infrared, time-domain analysis of nonlinear phenomena and detailed investigations of strong-field light–matter interactions. An on-chip, sub-optical-cycle sampling technique for measuring arbitrary electric fields of few-femtojoule near-infrared optical pulses in ambient conditions is demonstrated, offering an improvement of roughly six orders of magnitude in energy sensitivity compared with those previous works in the near-infrared.