Overview
![](/assets/images/picto-drapeau-france-3a76576a5d60a512053b4612ab58dae5.png)
ABSTRACT
Widespread fiber-optic network deployments have created new requirements in Fiber Characterization (FC) processes and tools. FC defines a series of tests that must be done to qualify a fiber infrastructure. The Optical Time Domain Reflectometer (OTDR) has become one of the key elements in the FC toolbox. Unlike loss test sets, the OTDR is designed to provide a single-ended measurement and can measure both attenuation and distance of events or faults all along the network. This article describes the OTDR measurement principle, the measurement configuration, the different measurements and their interpretation together with recommendations for product use.
Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.
Read the articleAUTHOR
-
André CHAMPAVÈRE: Head of R&D Analog and Optic Design - Head of Innovation & IP Protection Center of Excellence for VIAVI Solutions R&D centers - Honorary Chairman of ARUFOG (Association pour la Recherche et l'Utilisation de Fibre Optique et de l'Optique guidée) and creator and leader of the GO2S® (Guided Optics and Sensor Systems) initiative. - Expert member of ISROS (International Society on Reliability of Optoelectronics for Systems) - GuidOptix® Independent Scientific Expert - Member of IEEE and OSA (Optical Society)
INTRODUCTION
Originally, fiber-optic networks underwent a limited number of tests before they were actually put into service. Increasing data rates to several tens of gigabits per second, wavelength multiplexing using CWDM (Coarse Wavelength Division Multiplexing), DWDM (Dense Wavelength Division Multiplexing) or even DWDM over CWDM, and the extension of the transmission spectral window to the O, E, S and L bands (1,260 to 1,625 nm) soon made it imperative to supplement distance and attenuation measurements with more detailed characterization of the infrastructure's performance. Fiber characterization thus encompasses a list of measurements to be carried out to determine the network's ability to meet current and future transmission requirements, and thus to qualify it before it is commissioned or upgraded. The combination of a number of measuring devices today enables us to measure distances, linear fiber attenuation, insertion loss and reflectance, ORL (Optical Return Loss), CD (Chromatic Dispersion), PMD (Polarization Mode Dispersion) and spectral attenuation or attenuation profile.
The extensive capabilities of the Optical Time Domain Reflectometer (OTDR) make it the key measurement device in this family of fiber optic network characterization tools.
In the majority of applications, the optical reflectometer has supplanted the radiometric method, which required the connection of a radiometer and a source on either side of the link. A kind of optical radar, the reflectometer requires access to only one end of the link under test, thus necessitating the presence of a single operator.
In some cases, certain characterization measurements may be considered optional. On the other hand, the distance and attenuation measurements provided by the OTDR are essential.
In the following pages, we focus on the use of optical reflectometry in the characterization of optical fiber networks. Despite some similarities, we will not deal with the case of characterization in fiber or cable production, but will remain focused on the application to networks.
This is followed by a description of reflectometry, the physical phenomena involved and the reflectometer. After describing the principle and the tool, the use of the reflectometer, from its implementation and measurement to the analysis and interpretation of curves and results, is described, ending with a presentation of current trends towards the automation of fiber characterization by reflectometry.
The aim of this article is to provide the technical basis for reflectometry in its application to the characterization of telecommunication networks, whether long-, medium- or short-distance, such as fiber-to-the-home (FTTH) access networks. We...
Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference
KEYWORDS
fiber optic | reflectometry | OTDR | network | telecom
CAN BE ALSO FOUND IN:
This article is included in
Networks and Telecommunications
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Optical fiber and network characterization using reflectometry
Bibliography
Standardization
- Laser safety – Part 1: Equipment classification and requirements - NF EN 60825-1 - 01-08
- Calibration of optical time domain reflectometers (OTDR) – Part 1: OTDR for single-mode fibers - NF EN 61746-1 - 2014
- Laser safety – Part 1: Equipment classification, specifications and user guide - IEC 60825-1 - 1998
- Calibration of optical time-domain reflectometers (OTDR) – Part 1: OTDR for single mode fibres...
Training
Organization ARUFOG Training reference n° 08-FOR : OTDR : Operation, use and interpretation of results – Trainer CHAMPAVÈRE (A.) (VIAVI) http://www.arufog.org
Solutions/GuidOptix http://www.guidoptix.com
Directory
Main manufacturers – Field reflectometer manufacturers
• French manufacturer/European manufacturers :
VIAVI (ex-Schlumberger, Enertec, WWG, Acterna, JDSU) https://www.viavisolutions.com/fr-fr
(Note: Fiber Optics Division, R&D and reflectometer production at Saint-Étienne)
...Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference