Modern fiber optic networks usually keep splice loss low, as shown below: You should know that each splice can add 0. If losses add up, you may face poor signal quality and need more maintenance. This helps the. Fiber splice loss measures how much signal drops when you join two fiber ends. Unfortunately, it is not a simple answer and depends on several factors. So how do you determine acceptable loss? When testing fiber optic cabling, determining acceptable loss is. Mode field mismatch and alignment mechanisms cause loss when splicing, though it is possible to encourage diffusion across the join to reduce loss. By classification, there are.