Fast Characterization of Dispersion and Dispersion Slope of Optical Fiber Links using Spectral Interferometry with Frequency Combs

TL;DR

This paper introduces a rapid method using spectral interferometry with frequency combs to measure dispersion and dispersion slope in long optical fibers within microseconds, enabling real-time fiber monitoring.

Contribution

The novel approach combines spectral interferometry with frequency combs for fast, long-distance fiber characterization, surpassing previous meter-scale limitations.

Findings

Achieved ~1.4 microseconds measurement time.

Successfully characterized 25 km fiber links.

Potential for real-time fiber monitoring and stabilization.

Abstract

We demonstrate fast characterization (~1.4 microseconds) of both the dispersion and dispersion slope of long optical fiber links (~25 km) using dual quadrature spectral interferometry with an optical frequency comb. Compared to previous spectral interferometry experiments limited to fiber lengths of meters, the long coherence length and the periodic delay properties of frequency combs, coupled with fast data acquisition, enable spectral interferometric characterization of fibers longer by several orders of magnitude. We expect that our method will be useful to recently proposed lightwave techniques like coherent WDM and to coherent modulation formats by providing a real time monitoring capability for the link dispersion. Another area of application would be in stabilization of systems which perform frequency and timing distribution over long fiber links using stabilized optical frequency combs.