The pure-quartic soliton laser

TL;DR

This paper introduces a novel ultrafast laser that generates pure-quartic soliton pulses by leveraging fourth-order dispersion, enabling higher pulse energy and opening new avenues in nonlinear optics.

Contribution

It demonstrates the first mode-locked laser producing pure-quartic solitons through high-order dispersion management, a significant departure from traditional second-order dispersion control.

Findings

Pure-quartic soliton pulses are generated in a mode-locked laser.

Pulse energy scales with the cube of inverse pulse duration.

Higher-order dispersion can be strategically used for pulse control.

Abstract

The generation of ultrashort pulses hinges on the careful management of dispersion. Traditionally, this has exclusively involved second-order dispersion, while higher-order dispersion was treated as a nuisance to be minimized. Here we show that high-order dispersion can be strategically leveraged to access an uncharted regime of ultrafast laser operation. In particular, we demonstrate a mode-locked laser, with an intra-cavity spectral pulse-shaper, that emits pure-quartic soliton pulses, which arise from the interaction of the fourth-order dispersion and the Kerr nonlinearity. Using phase-resolved measurements we demonstrate that the energy of these pulses is proportional to the third power of the inverse pulse duration. This implies a dramatic increase in the energy of ultrashort pulses compared to those emitted by soliton lasers to date. These results not only demonstrate a novel approach to ultrafast lasers, but more fundamentally, they clarify the use of higher-order dispersion for optical pulse control, opening up a plethora of possibilities in nonlinear optics and its applications.