AbstractAn interferometer capable of retrieving the phase information in a single shot was implemented, the system was made by taking into account the double interferogram output obtained in a Mach Zehnder interferometer and then retrieving the phase information using a two-step algorithm already encountered in the literature. By controlling the polarization properties of the system, a new polarization phase shifting technique was implemented based upon the rotation of two quarter wave retarders placed in each of the arms of the interferometer. We present the analytical model taking into account the necessary conditions presented by the demodulation method. The configuration presented does not require micro-polarizer arrays or diffraction gratings presenting the advantage of avoiding the use of conventional polarizing filters to control the phase shift. Experimental results are presented.