Polarization measurement with polarizer only

Polarization measurement with polarizer only is presented.Compared with the traditional polarization measurements,this method needs less equipment and can measure the polarization state and polarization distribute of plane wave.Through rotating one polarizer it can measure all kinds of polarization state,except circularly polarized light and natural light.Another low extinction coefficient polarizer is set before the first polarizer,then the circularly polarized light converts to elliptically polarized light,and natural light converts to partially polarized light.Therefore these two exceptions can be distinguished.This method is very applicable in lithography system with less cost and more accuracy and practicability.