Temporal Cavity Solitons in a Laser-based Microcomb: A Path to a Self-Starting Pulsed Laser without Saturable Absorption

TL;DR

This paper proposes a theoretical design for a self-starting microcomb system utilizing laser-cavity solitons, enabling pulsed laser operation without the need for saturable absorption, by engineering modulational instability.

Contribution

It introduces a novel approach to generate self-starting microcombs using laser-cavity solitons, avoiding traditional gain saturation techniques.

Findings

System can start with a well-defined number of solitons

Control of soliton number and repetition rate via system parameters

Provides an alternative to standard mode-locking methods

Abstract

We theoretically present a design of self-starting operation of microcombs based on laser-cavity solitons in a system composed of a micro-resonator nested in and coupled to an amplifying laser cavity. We demonstrate that it is possible to engineer the modulational-instability gain of the system's zero state to allow the start-up with a well-defined number of robust solitons. The approach can be implemented by using the system parameters, such as the cavity length mismatch and the gain shape, to control the number and repetition rate of the generated solitons. Because the setting does not require saturation of the gain, the results offer an alternative to standard techniques that provide laser mode-locking.