High-speed optical correlation-domain reflectometry without using acousto-optic modulator

TL;DR

This paper presents a simplified, cost-effective optical correlation-domain reflectometry system that eliminates the need for an acousto-optic modulator, enabling high-speed distributed fiber reflectivity measurements with real-time tracking.

Contribution

It introduces a novel configuration that synthesizes the optical coherence function via sinusoidal modulation, reducing bandwidth requirements and simplifying the system.

Findings

Achieved high-speed measurement with 10 ms scan time

Demonstrated real-time tracking of a moving reflection point

Lowered electrical bandwidth to several megahertz

Abstract

To achieve a distributed reflectivity measurement along an optical fiber, we develop a simplified cost-effective configuration of optical correlation- (or coherence-) domain reflectometry based on a synthesized optical coherence function by sinusoidal modulation. By excluding conventional optical heterodyne detection (practically, without using an acousto-optic modulator) and by exploiting the foot of the Fresnel reflection spectrum, the electrical bandwidth required for signal processing is lowered down to several megahertz. We evaluate the basic system performance and demonstrate its high-speed operation (10 ms for one scan) by tracking a moving reflection point in real time.