Toward the generation of high-energy temporal solitons in a free-space enhancement cavity

Abstract: 

A soliton is a wave packet that retains its shape as it propagates due to a balance between the dispersion and non-linear response of a medium. These wave packets have garnered interest in the areas of frequency generation and ultrafast laser mode-locking due to their stability and self-reinforcing properties. Here, we describe the development of a system designed to be capable of generating such a wave packet in a free-space ultrafast enhancement cavity. This consists of three main parts: a homemade ultrafast fibre laser system, the enhancement cavity itself, and a frequency locking system to stabilize the laser output relative to the cavity resonances. The laser is capable of outputting up to 4 W average power and pulse durations on the order of 200 fs, while the overall system has so far demonstrated an average power enhancement factor of 204, corresponding to a potential intracavity average power of more than 800 W. This demonstrates the potential of this platform to support soliton generation, allowing one to study soliton dynamics or improve upon current intracavity non-linear frequency conversion processes.