APPARATUS AND METHOD FOR MEASURING POLARIZATION-DEPENDENT LOSS USING REPEATED HIGH SPEED POLARIZATION SCRAMBLING

摘要

Disclosed is an apparatus and method for measuring a changing amount ofinsertion loss of an optical device depending on a polarization state of anincident light, i.e., a polarization-dependent loss. An incident light that isperiodically subject to all polarization states passes through a testingoptical device by a polarization scrambler including a piezoelectric elementtype optical fiber birefringence modulator, and an optical detector measuresintensity of the passing light, in which the measured intensity values areaveraged for birefringence modulation having a constant period, and then thepolarization-dependent loss is computed from a ratio of maximum power tominimum power for the period. Use of the birefringence modulator shortensmeasuring time, and decreases an affect of external disturbance to theincident light that is incident into the testing optical component oroccurrence probability of the external disturbance, so that the polarization-dependent loss can be precisely measured.