Instrumentation principles for optical time domain reflectometry

Abstract

Optical time domain reflectometry (OTDR) is the only fibre measurement technique which allows anomalously lossy sections of fibre and other defects to be located nondestructively from one end of the fibre. The paper reviews the principles and techniques of the method. The material covered ranges from a brief background introduction to the physics of Rayleigh backscattering in optical fibres, through to the wide range of instrumentation techniques that have been designed to measure this signal.