Accurate Single-Ended Measurement of Propagation Delay in Fiber Using Correlation Optical Time Domain Reflectometry

TL;DR

This paper introduces a correlation optical time-domain reflectometry method that accurately measures fiber propagation delay with picosecond precision using high data rate signals and advanced signal processing techniques.

Contribution

The paper presents a novel COTDR approach combining cross-correlation and pulse fitting for highly precise delay measurements in fiber optics.

Findings

Achieves measurement accuracy of a few picoseconds.

Effective for monitoring link delay and chromatic dispersion.

Applicable to temperature sensing in long fiber spans.

Abstract

A correlation optical time-domain reflectometry (COTDR) method is presented, which measures the propagation delay with an accuracy of a few picoseconds. This accuracy is achieved using a test signal data rate of 10 Gbit/s and employing cross-correlation and pulse fitting techniques. In this paper we introduce and evaluate the basic signal processing steps, investigate the measurement accuracy, and discuss applications for monitoring link delay and chromatic dispersion of long fiber spans as well as temperature sensing applications.