# Coherently controlled generation of single-cycle terahertz pulses from thin layer of nonlinear medium with low-frequency resonances

## TL;DR

This paper introduces a new method for generating single-cycle terahertz pulses by reflecting femtosecond pulses from a nonlinear resonant medium, enabling efficient and tunable THz wave production.

## Contribution

The paper presents a novel scheme utilizing coherent control of low-frequency oscillations in a thin nonlinear medium for single-cycle THz pulse generation.

## Key findings

- The method achieves wave shape tunability of THz pulses.
- High efficiency in single-cycle THz pulse generation demonstrated.
- The approach is simple and suitable for near-field detection.

## Abstract

We propose a novel scheme to generate single-cycle terahertz (THz) pulses via reflection of an optical femtosecond pulse train from a thin layer of nonlinear resonant medium. Our method is based on a coherent control of low-frequency oscillations and free induction decay in the medium. The specific single-cycle shape of generated THz pulses requires a plane wavefront and detection in the near field. Our theoretical results pave the way to a new, simple and high-efficiency way to generate single-cycle waveshape-tunable terahertz pulses.