The primary contributors to measured splice loss are fiber material and design factors that prevent an optimal coupling of the light pulses from one fiber end to another. The total loss in decibels at the fusion splice is given by the following equation, where Pin is the total power incident on the fusion splice and Ptrans is the. Fiber loss can be also called fiber optic attenuation or attenuation loss, which measures the amount of light loss between input and output. Factors causing fiber loss are various, such as intrinsic material absorption, bending, connector loss, etc. Imperfect coupling means that some of the light coming from the first fiber gets into. Are you looking for ways to improve the performance of your fiber optic splices? If so, you've come to the right place.