Nonlinear Dynamics in Semiconductor Lasers 2023 - Abstract

Razumov, Aleksandr

Phase noise source separation for frequency combs

An understanding of how internal and external phase noise sources affect spectral comb lines is critical for applications involving optical frequency combs. In many practical situations, we may not have an accurate understanding, and a model for, how, and how many, independent phase noise sources contribute to the overall phase noise of each comb line. We propose a measurement method based on subspace tracking, in combination with multi-heterodyne coherent detection, for independent phase noise sources identification, separation and measurement. We experimentally demonstrate that the proposed measurement method is able to identify and measure independent phase noise sources associated with an electro-optic comb and a comb based on a semiconductor frequency modulated mode-locked laser, for which noise sources are less well understood.