Phase-locked multi-terahertz electric fields exceeding 13 MV/cm at 190 kHz repetition rate

TL;DR

This paper presents a compact, high-repetition-rate source of phase-locked multi-terahertz pulses with high electric fields, enabling advanced strong-field terahertz applications.

Contribution

The authors demonstrate a novel, scalable method to generate phase-locked multi-terahertz pulses exceeding 13 MV/cm at 190 kHz.

Findings

Achieved peak electric fields of 13 MV/cm

Generated tunable THz pulses between 12 and 42 THz

Maintained phase stability better than 0.1 π over hours

Abstract

We demonstrate a compact source of energetic and phase-locked multi-terahertz pulses at a repetition rate of 190 kHz. Difference frequency mixing of the fundamental output of an Yb:KGW amplifier with the idler of an optical parametric amplifier in GaSe and LiGaS2 crystals yields a passively phase-locked train of waveforms tunable between 12 and 42 THz. The shortest multi-terahertz pulses contain 1.8 oscillation cycles within the intensity FWHM. Pulse energies of up to 0.16 {\mu}J and peak electric fields of 13 MV/cm are achieved. Electro-optic sampling reveals a phase stability better than 0.1 $\pi$ over multiple hours combined with free CEP tunability. The scalable scheme opens the door to strong-field terahertz optics at unprecedented repetition rates.