Effective Path Towards Relativistic Transients at Millimeter Wavelengths

TL;DR

This paper presents a novel method for generating high-field, relativistic sub-terahertz transients in the millimeter wavelength range using spatio-temporal shaping of optical pulses in lithium niobate, enabling advanced terahertz applications.

Contribution

The authors introduce an innovative spatio-temporal shaping technique that significantly enhances the efficiency and electric field strength of sub-THz transients generated via optical rectification.

Findings

Achieved near diffraction-limited sub-THz transients with 0.2 GV/m fields.

Demonstrated efficient generation using only mJ-level optical pulses.

Provided both experimental and theoretical analysis of the method.

Abstract

We refine the method towards extraction of sub-cycle transients in the 0.1-1 THz frequency (mm-wavelength) range from optical rectification in lithium niobate using tilted pulse fronts. Our scheme exploits previously unexplored spatio-temporal shaping of the pump pulses, resulting in highly efficient and near diffraction-limited sub-THz transients reaching 0.2 GV/m electric field strengths in free-space using only mJ-level optical ps-pulses. We address experimentally and theoretically the means to producing above-GV/m relativistic sub-THz transients with proper beam confinement and under moderate pumping conditions, thereby bringing widespread access to strong-field and nonlinear terahertz applications and devices.