Fiber Optics – Light Brigade Practice Test

The key idea is where the reflection is measured. Reflectance refers to the amount of light that bounces back from a single interface, such as a specific connector endface or splice. It’s a point measurement tied to that one junction.

Optical Return Loss looks at back-reflected light from the entire optical path back toward the source. It combines reflections from multiple interfaces along the link (connectors, splices, fiber ends, etc.), giving a system-wide or total measure of how much light returns.

So reflectance is a single-point measurement, while ORL represents the total back-reflected power from the whole path. It’s not about forward loss, which is the attenuation in the forward direction.