Origin and stability of dark pulse Kerr combs in normal dispersion resonators

TL;DR

This paper investigates the origin and stability of dark pulse Kerr frequency combs in normal dispersion resonators, revealing their connection to switching waves and providing a stability map, challenging the role of modulational instability.

Contribution

It introduces a novel analysis linking dark pulse Kerr combs to interlocked switching waves and offers a detailed stability map in parameter space.

Findings

Dark pulse Kerr combs correspond to interlocked switching waves.

Modulational instability is not involved in their existence.

Stable regions and destabilization conditions are mapped.

Abstract

We analyze dark pulse Kerr frequency combs in optical resonators with normal group-velocity dispersion using the Lugiato-Lefever model. We show that in the time domain these correspond to interlocked switching waves between the upper and lower homogeneous states, and explain how this fact accounts for many of their experimentally observed properties. Modulational instability does not play any role in their existence. Furthermore, we provide a detailed map indicating where stable dark pulse Kerr combs can be found in parameter space, and how they are destabilized for increasing values of frequency detuning.