Abstract: Mitigating back reflection in fiber optic cables when coupling two fiber optic cables, for example, for implementing in harsh environments including wellbores. As described below, light from a source can travel toward a target through a first fiber optic cable and a second fiber optic cable coupled to the first fiber optic cable using a coupling system. The two fiber optic cables can be coupled such that all or a portion of back reflection at the coupling part is absorbed rather than permitted to travel back toward the source through the first fiber optic cable.