Exceptional point proximity-driven mode-locking in coupled microresonators
Abstract
We show theoretically and numerically that mode-locking is feasible with a coupled-cavity system with gain and loss, notably, without any natural saturable absorber. We highlight that in the vicinity of the exceptional point, system exhibits substantial modulation even with minor refractive index changes and a minimal Kerr effect contribution. Leveraging this unique behaviour, we propose an unprecedented approach wherein the lossy auxiliary cavity functions as an efficient artificial saturable absorber, thus facilitating mode-locking. This approach is not only novel, but also presents considerable advantages over conventional systems where both gain and saturable absorption are contained within a single microcavity. These benefits include reduced operational power and ease of post-adjustment, achievable through the manipulation of the coupling strength between the two microcavities.
Cite
@article{arxiv.2309.05912,
title = {Exceptional point proximity-driven mode-locking in coupled microresonators},
author = {Riku Imamura and Shun Fujii and Ayata Nakashima and Takasumi Tanabe},
journal= {arXiv preprint arXiv:2309.05912},
year = {2023}
}