What is 'back reflection' in fiber optics?

Back reflection in fiber optics refers to light that is reflected back towards the source from the ends of the optical fiber. This phenomenon occurs when light travels through the optical medium and encounters a change in the medium at the fiber ends or at junctions; a portion of this light is reflected back along the path it came from. This is significant in optical networks because excessive back reflection can lead to signal loss and degraded performance of optical transmission systems.

In contrast, the other definitions include aspects that either do not accurately describe back reflection or pertain to different phenomena. The reflection from external light sources typically relates more to environmental interferences rather than the intrinsic properties of the fiber itself. Light escaping from bends involves signal attenuation due to physical distortions of the fiber, not specifically back reflection. Additionally, light reflecting from the outer jacket of the fiber cable does not pertain to the concept of back reflection, which primarily focuses on light behavior at the fiber core.