Return loss in fiber optic connections can significantly degrade system performance. Connections will exhibit return loss even if they are perfectly clean and possess ideal geometries. This paper explains how the complexities of different physical connections contribute to return loss, such as:
- Contributions from small refractive index differences between fibers
- Damage caused by endface polishing
- Fiber deformation due to the connector spring force
This paper also explains how an angle polished on the fiber and connector helps to significantly reduce the return loss by directing reflected light at the endface of the connector out of the fiber core, hence reducing the light traveling back towards the source.