Insertion loss

Light or signal energy that is lost as the signal passes through the optical fiber end in the connector and is inserted into another connector or piece of hardware. A good connector minimizes insertion loss to allow the greatest amount of light energy through. A critical measurement for optical fiber connections. Insertion loss is measured by determining the output of a system before and after the device is inserted into the system. Loss in an optical fiber can be due to absorption, dispersion, scattering, microbending, diffusion, and the methods of coupling the fiber to the power. Usually measured in dB per item; for example, a coupler, connector, splice, or fiber. Most commonly used to describe the power lost at the entrance to a waveguide (an optical fiber is a waveguide) due to axial misalignment, lateral displacement, or reflection that is most applicable to connectors.