Error analysis on two-waveplate polarization state transformers by geometry method

The polarization transform errors of two-waveplate polarization state transformers (TWPST), which consist of quarter-waveplate (QWP) and half-waveplate (HWP), are discussed in detail. The error model of the TWPST based on a new and simple two dimensions geometry method instead of traditional Poincaré sphere method or Jones matrix method are proposed. We did the numerical calculations based on the error model of the TWPST. The results show that the output polarization state errors of the TWPST are chiefly sensitive to the azimuth angle errors of the QWP, and that there exist a pair of optimal error azimuth angles of QWP and HWP, which can minimize the azimuth angle error of the output polarization state of TWPST, and that the ellipticity error of output polarization state of TWPST is dependent only on the azimuth angle errors of QWP. The TWPST have enough accuracy to evaluate the polarization related effects (PRE) in the optical communication systems.