OTDR

An Optical Time Domain Reflectometer (OTDR) is an important instrument used by organizations to certify the performance of new fiber optics links and detect problems with existing fiber links.

Optical Time Domain Reflectometer equipment is designed to characterize optical fiber. An OTDR trace is done by sending an optical pulse down the fiber optic cable. This light signal is reflected back from the sides of the fiber. The light is scattered in many directions including back to the source. This backscattered light is what the OTDR measures. The process is repeated and averaged so as to represent the characteristics of the tested fiber. Measuring the strength of this return light signal, the OTDR can estimate fiber length. In addition, testing can determine the location of events such as splice loss, overall attenuation or breaks within the fiber cable. OTDRs are available with a variety of fiber types and wavelengths which include; 1625nm, 1550nm, 1490nm, 1310nm, for single mode. Multi-mode units typically carry 850nm and 1300nm wavelengths.