What tool is used to measure insertion loss in fiber optics?

The tool used to measure insertion loss in fiber optics is the combination of a light source and power meter. This method involves sending a known amount of light through the fiber optic link from the light source and measuring the amount of light that arrives at the other end with a power meter. The insertion loss can then be calculated by comparing the output power at the light source to the input power received at the power meter. This provides a direct measurement of the total loss in the fiber optic link, considering factors such as attenuation and connector losses.

Using a visual fiber tracer is more about identifying faults or continuity in the fiber rather than measuring specific loss metrics like insertion loss. A fiber optic power meter, while it can measure power levels, does not include a light source, making it unable to measure the insertion loss on its own without a known reference level. An OTDR (Optical Time Domain Reflectometer) is utilized for testing and troubleshooting fiber optic cables, providing information about splice and connector locations as well as distance measurements, but it is not specifically used to measure insertion loss in the straightforward manner that a light source and power meter do. Therefore, the combination of a light source and a power meter is the correct choice for measuring insertion loss.