Abstract: In order to calibrate an apparatus for measuring the polarization dependent loss of an optical device under test, a set of nominal polarization states of incident light are generated with a polarization generator. The incident light is then passed through a dot-product conserving polarization rotator at a first setting. A transmission characteristic is measured through a standard optical component with a known polarization dependent loss value for each polarization state. This step is repeated for a number of different settings of the polarization rotator. A polarization dependent loss value is calculated for the standard optical component based on the measured transmission characteristics at each polarization rotator setting. The calculated polarization dependent loss values are then processed to generate an aggregate error value.