Temporal Slicing of Intense Multi-THz Transients Using an Ultrafast Semiconductor Switch

Abstract

Advances in the femtosecond THz opto-electronics have set the stage for a novel class of nonlinear optical experiments exploiting the extreme limits of light-matter interaction. The spectral range of phase-stable multi-THz transients generated by means of difference frequency mixing spans over a multi-octave frequency window. Simultaneously, field-sensitive electro-optic detection provides full access to the temporal pulse shape. Currently, phase-locked multi-THz transients range from multi-cycle waveforms with highest peak electric fields in excess of 100 MV/cm [1] down to a single oscillation of the carrier wave with maximum field above 10 MV/cm [2]. Generally, the interaction length within the emitter crystal yields a trade-off between peak electric field and spectral bandwidth [2]. It would be desirable to combine the advantages of highest peak electric fields and short pulse durations in a single waveform. A promising tool for this purpose is a switching technique based on an ultrafast plasma mirror (UPM)Here, we present a scheme that employs an ultrafast plasma mirror (UPM) to slice intense multi-THz transients from our high-field THz laser source with a sub-cycle precision. For the first time, to the best of our knowledge, the fastest temporal slicing of multi-THz transients is observed using a field-resolved electro-optic detection scheme.