The theoretical split loss is 10·log 10 (8) = 9. Summing all allowances yields a total branch loss of 12. 83 dB, which should be recorded in the project test plan. The fix? Replace every splitter, re-splice the distribution fibers, and re-run the entire link budget from. A passive optical splitter divides an incoming light signal across two or more output ports. Common ratios: For cascades, add losses and validate margin using the Optical Budget tool. Let's say you have a laser output at 0 dBm (which is 1 milliwatt of optical power). 5 dBm This means each output port now only carries about 0.