Optical cable technology — testing

Abstract

This chapter illustrates that optical cable links might be tested using an Optical Time Domain Reflectometer (OTDR) or by an optical power meter and light source. In practice, it is much simpler to use an optical power meter and just use an OTDR for fault finding. For larger projects, the end-user customer might often insist on OTDR trace results to characterize the fiber, but few people understand the significance of what they see on OTDR traces. For short haul datacom links, the optical power meter method is quickest and cheapest and allows for the fastest interpretation of results. All optical test reports must include a table of link loss results either from a power meter or derived from OTDR traces. If a problem does arise, the installer must have access to an OTDR for fault finding purposes. To be useful, the test results must be correctly documented. Handheld testers for copper cable store all the test data in an appropriate format but it is not so straightforward for optical results.