Single-cycle gap soliton in a subwavelength structure

TL;DR

This paper demonstrates the generation of single-cycle optical pulses using subwavelength structures in dense media, revealing a new way to produce ultra-short laser pulses beyond traditional approximations.

Contribution

It reports the observation of single-cycle gap solitons in full Maxwell-Bloch equations without common simplifying assumptions, highlighting the role of subwavelength structures in pulse shaping.

Findings

Single-cycle gap solitons can form in subwavelength structures.

Subwavelength structures suppress intrapulse four-wave mixing effects.

Formation of solitons occurs even when the Bragg condition is broken.

Abstract

We demonstrate that a single sub-cycle optical pulse can be generated when a pulse with a few optical cycles penetrates through resonant two-level dense media with a subwavelength structure. The single-cycle gap soliton phenomenon in the full Maxwell-Bloch equations without the frame of slowly varying envelope and rotating wave approximations is observed. Our study shows that the subwavelength structure can be used to suppress the frequency shift caused by intrapulse four-wave mixing in continuous media and supports the formation of single-cycle gap solitons even in the case when the structure period breaks the Bragg condition. This suggests a way toward shortening high-intensity laser fields to few- and even single-cycle pulse durations.