A method may include injecting a test signal having a first optical launch power into a device under test via an optical splitter. The optical splitter includes at least two upstream ports and a downstream port and the test signal is injected in a first upstream port of the optical splitter. The device under test is coupled to the downstream port. Return loss associated with the device under test is measured at a second upstream input of the optical splitter. The RL measurement in stored a database. The injecting, measuring, and storing are repeated for a number of different optical launch powers.