Vector projection method used for calibration of the polarimeter module

Abstract

To solve the problem of calibrating the polarimeter module, we design a vector projection (VP) method which is based on the theorem of vector projection and the principle of calibration. The calibration matrix can be calculated by VP method with the given data. The experimental result shows that, in comparison with the common iterative algorithm, VP method has very high computational efficiency and accuracy. The measured error of the degree of polarization (DOP) is less than 3%. OCIS codes: 060.2330, 060.4510. doi: 10.3788/COL201210.S20607. Measuring the state of polarization (SOP) of light signal in fiber is one of the important issues in optical fiber communication system, in which we can get the degree of polarization (DOP) of the signal in fiber links to compensate PMD in the fiber, or get the SOP in the polarization stabilizers [1 7] , etc. In generally, a polarimeter includes optical part and electrical driver part (the four paths linear amplification, high-speed analog to digital converter, etc.). The outputs of the polarimeter are four voltages. In order to get Stokes vectors, a transformed matrix is needed. While for different input wavelengths, the transformed matrix has a little difference. So calibration of transformed matrix is an important but a complicated task. A fast and reliable calibration method should be established. In this letter, we proposed a new method to calibrate the transformed matrix by using the data getting from a reference polarimeter, such as N7788BD (Angilent Technologies). This method is based on the vector projection algorithm.