When using a fusion splicer, the typical splice loss is usually between 0. 05 dB for single-mode fibre and slightly higher for multimode fibre. 1 dB is generally considered acceptable in most fibre optic networks. This tool uses the Marcuse Gaussian Approximation to calculate losses from intrinsic mismatch and extrinsic alignment errors. Enter values based on recent OTDR traces, contractor QA records, or manufacturer guidance. 1 dB/splice (worst case) then we arrive at the following. Splice loss refers to the part of the optical power that is not transmitted through the splice and is. High-quality fusion splices may reach values like 0. For high-power devices, a high insertion loss is often unwanted not only due to the power loss but also because of possibly strong heating effects resulting from absorbed light.