Equivalence analysis of retarder compose of three wave plates

For light of a given wavelength, an optical system containing several retardation plates is optically equivalent to a system containing only two elements-one is retardation plate, and the other is a rotator. In this paper, by means of Jones matrix, we have studied the system containing three plates, which can work as only one pure retarder without rotator if the conditional equation is satisfied. The governing equations for equivalence is deduced, which determine the overall system retardation and azimuth. The general condition equations are discussed in detail and several particular cases are simulated. This method is instructive and convenient for compound retarders designing.