Calculation formula: IL = -10 lg (Pout / Pin), Pout is the output optical power, and Pin is the input optical power. The smaller the value of the insertion loss, the better the performance. We offer full-service OEM and ODM solutions for fiber optic cables, assemblies, and connectivity products — from design and prototyping to global production and logistics. This is a good page to bookmark on your smartphone, tablet and/or laptop to have for making calculations in the field.