Characterizing pump line phase offset of a single-soliton Kerr comb by dual comb interferometry

TL;DR

This paper demonstrates a rapid, low-power method for phase retrieval of single-soliton Kerr combs using dual-comb interferometry, revealing phase offsets influenced by pumping parameters.

Contribution

It introduces an all-linear, dual-comb interferometry technique for fast phase measurement of Kerr combs, with experimental validation and numerical agreement.

Findings

Kerr comb phase profile is nearly flat.

Pump line exhibits phase offset depending on pumping parameters.

Method achieves rapid measurement in 3.2 microseconds with low input power.

Abstract

We experimentally demonstrate phase retrieval of a single-soliton Kerr comb using electric field cross-correlation implemented via dual-comb interferometry. The phase profile of the Kerr comb is acquired through the heterodyne beat between the Kerr comb and a reference electro-optical comb with a pre-characterized phase profile. The soliton Kerr comb has a nearly flat phase profile, and the pump line is observed to show a phase offset which depends on the pumping parameters. The experimental results are in agreement with numerical simulations. Our all-linear approach enables rapid measurements (3.2 $\mu$s) with low input power (20 $\mu$W).