Patent ID: 7633607
Filing Date: 2009-12-15
Classification: G01N

Abstract:
1. A method for calibrating an apparatus for measuring one or more characteristics of an optical element, comprising the following steps: (a) providing a calibration path for the apparatus; (b) performing a calibration operation using the calibration path, wherein the calibration operation may be performed without the optical element having to be operatively de-coupled from the apparatus; and (c) calibrating the apparatus based on the calibration operation during a time period when the optical element is operatively coupled to the apparatus, wherein the calibration path includes a fiber loop polarization controller that remains in the calibration path even when the optical element under test is coupled to the apparatus; (d) moving the polarization controller to multiple positions; (e) determining one or more calibration corrections for the apparatus at each of the multiple positions of the polarization controller; and (f) using the one or more calibration corrections to update the calibration.