Terahertz wave generation from hyper-Raman lines in two-level quantum systems driven by two-color lasers

TL;DR

This paper introduces a new method for generating tunable terahertz waves using hyper-Raman lines in a two-level quantum system driven by two-color lasers, leveraging symmetry breaking and quasi-energy analysis.

Contribution

It proposes a novel scheme for THz wave generation from hyper-Raman lines, enabling frequency tuning and strong emission in the THz regime.

Findings

Frequency of THz wave can be tuned by laser amplitude.

Arbitrary THz frequencies can be generated with strong intensity.

The scheme is feasible with current experimental techniques.

Abstract

Based on spatial-temporal symmetry breaking mechanism, we propose a novel scheme for terahertz (THz) wave generation from hyper-Raman lines associated with the 0th harmonic (a particular even harmonic) in a two-level quantum system driven by two-color laser fields. With the help of analysis of quasi-energy, the frequency of THz wave can be tuned by changing the field amplitude of the driving laser. By optimizing the parameters of the laser fields, we are able to obtain arbitrary frequency radiation in the THz regime with appreciable strength (as strong as the typical harmonics). Our proposal can be realized in experiment in view of the recent experimental progress of even-harmonics generation by two-color laser fields.