Gap loss

Gap loss is a type of signal strength loss that occurs in fiber optic transmission when the signal is transferred from one section of fiber or cable to another.

The three basic types of gap loss are angular misalignment loss, lateral offset loss, and longitudinal displacement loss. The losses tend to be proportional to the ratio of the core radius to the size of the gap or displacement. Formulas, examples and graphs can be found at Fiber Optic Communication - Couplers and Connectors Gap loss can be reduced by filling the gap with a gel that matches the index of refraction of the fiber as closely as possible.