Testing the quality of a fiber optic cable involves a combination of visual inspections, OTDR analysis, power meter and light source measurements, and additional tests for insertion loss, return loss, chromatic dispersion, and polarization mode dispersion. Testing fiber cable quality is a mandatory engineering process, not an optional best practice. Quality verification ensures that optical fibers meet attenuation, continuity, geometry, and mechanical integrity requirements before being placed into service. Note: most failures are due to lack of proper end-face cleaning while baked-on contamination. Fiber Optic Testing Testing is used to evaluate the performance of fiber optic components, cable plants and systems. As the components like fiber, connectors, splices, LED or laser sources, detectors and receivers are being developed, testing confirms their performance specifications and helps. There are three main principles that needs to be taken in consideration for an efficient optical connection: a perfect core alignment, perfect physical contact and dirt-free connectors. The primary reason for fiber inspection is to ensure that the connectors are free of any defects, damage, or debris that would prevent sufficient transmission of light when mated.