Frequency domain optical reflectometer

TLDR

The study presents a correlation reflectometer that operates in the frequency domain. The instrument employs frequency‑domain correlation to detect weak discrete reflections. It detects weak discrete reflections, demonstrates end‑reflection detection in a 2.2‑km fiber, achieves a round‑trip range of over 70 dB with a 1‑mW source, and shows promise for characterizing reflective properties of optical fiber elements such as tapers, microbends, and splices, aiding fault location.

Abstract

A correlation reflectometer operating in the frequency domain is described. It is shown that such an instrument is well adapted to detecting weak discrete reflections. The detection of end reflections in a 2.2-km length of fiber whose end is index matched is demonstrated. A round-trip range of over 70 dB is obtained with a 1-mW optical source power. The method shows promise for characterizing the reflective properties of optical fiber elements, such as tapers, microbends, and splices, and may be useful in fault location.