Spatiotemporal sampling of near-petahertz vortex fields

Abstract

Measuring the field of visible light with high spatial resolution has been challenging, as many established methods only detect a focus-averaged signal. Here, we introduce a near-field method for optical field sampling that overcomes that limitation by employing the localization of the enhanced near-field of a nanometric needle tip. A probe field perturbs the photoemission from the tip, which is induced by a pump pulse, generating a field-dependent current modulation that can easily be captured with our electronic detection scheme. The approach provides reliable characterization of near-petahertz fields. We show that not only the spiral wavefront of visible femtosecond light pulses carrying orbital angular momentum (OAM) can be resolved but also the field evolution with time in the focal plane. Additionally, our method is polarization sensitive, which makes it applicable to vectorial field reconstruction.

Lightwave Electronics: Attosecond Optical Switching

“…Moreover, a few-cycle (carrier-envelope phase (CEP)-controlled) laser pulse has been used to induce and control light-induced current in dielectric and nanocircuit. , The photoinduced current is generated due to the injection of electrons from the valence band to the conduction band of the material and enables a switching with a few femtoseconds speed based on controlling the CEP of the pump pulse. , This approach has been used to develop ultrafast light wave-based electronics ,, utilized for sampling the light field of ultrafast laser pulses by tracing the detected current in real time. ,− Moreover, an on-chip light field sampling optoelectronics was established based on inducing photoemission current from resonant nanoantennas. ,, In addition, light-based electronics using ultrafast terahertz waveform has been demonstrated , extending this capability to new spectral ranges.…”

Broadband Photoconductive Sampling in Gallium Phosphide

“…An alternative is presented by techniques that rely on the measurement of strong-field-induced charge carriers, such as nonlinear photoconductive sampling (NPS) [19] and tunneling ionization with a perturbation for the time-domain observation of an electric field (TIPTOE). [20][21][22][23][24] NPS relies on free carrier generation in a gas [25,26] or solid [19] between two electrodes with an ultrashort gate pulse, where the gate pulse is polarized perpendicular to the electrode axis. The carriers are then driven by a waveform-stable field, polarized along the electrode axis, causing a macroscopic current.…”

Synthesis and Direct Sampling of Single-Cycle Light Transients by Electron Tunneling in a Nanodevice

“…Nonlinear self-referenced pulse characterization techniques such as frequency-resolved optical gating (FROG) and spectral phase interferometry for direct electric field reconstruction (SPIDER) are limited by the phase-matching bandwidth of the used nonlinear crystal and hence cannot be used to characterize single-cycle laser pulses. Electric field sampling techniques using fast temporal gates, ,− such as attosecond streaking, allows for the sampling of the electric field waveforms in the near-infrared (NIR) to visible spectral range with an ultimate temporal resolution, although the generation of the ultrashort temporal gate requires intense light pulses (>1 μJ). Direct sampling of weak optical pulses (∼100 pJ) as available from a high-repetition-rate oscillator is challenging.…”