Two-states method for polarization dependent loss measurement

We report a two-states method for measuring polarization dependent loss (PDL) in an optical fiber system. Based on the property that the Mueller matrix governing the transmission property of any linear, time-invariant optical system with birefringence and PDL satisfies Lorentz transformation, we prove that PDL depends on the first column of the Mueller matrix. Hence only two orthogonal input polarization states are required to explicitly determine PDL. Experiment results show the agreement of our method with previously reported methods.